diff --git a/syamauchi/src/C020.java b/syamauchi/src/C020.java
new file mode 100644
index 0000000000000000000000000000000000000000..4475588cf66db88c3bba95dc4bb66db9ec49346e
--- /dev/null
+++ b/syamauchi/src/C020.java
@@ -0,0 +1,41 @@
+package src;
+
+import java.math.BigDecimal;
+import java.util.Scanner;
+
+public class C020 {
+  static BigDecimal PERCENTAGE = new BigDecimal("100");
+  private final String food;
+  private final String saleFood;
+  private final String saleSideDish;
+
+  public C020(final String food, final String saleFood, final String saleSideDish) {
+    this.food = food;
+    this.saleFood = saleFood;
+    this.saleSideDish = saleSideDish;
+  }
+
+  public static void main(String[] args) {
+    final Scanner sc = new Scanner(System.in);
+    final C020 food = new C020(sc.next(), sc.next(), sc.next());
+    System.out.println(food.calcUnsold());
+    sc.close();
+  }
+
+  // 誤差ができるのが嫌なのでBigDecimalを使用
+  public float calcUnsold() {
+    final BigDecimal food = new BigDecimal(this.food);
+    final BigDecimal saleFood = new BigDecimal(this.saleFood);
+    final BigDecimal saleSideDish = new BigDecimal(this.saleSideDish);
+
+    final BigDecimal percentageSaleFood = saleFood.divide(PERCENTAGE);
+
+    // food - food * percentageSaleFood
+    final BigDecimal unsold = food.subtract(food.multiply(percentageSaleFood));
+    final BigDecimal percentageSaleSideDish = saleSideDish.divide(PERCENTAGE);
+    // unsold - unsold * percentageSideDish
+    final BigDecimal allUnsold = unsold.subtract(unsold.multiply(percentageSaleSideDish));
+    //
+    return (allUnsold.floatValue());
+  }
+}
diff --git a/syamauchi/src/C052.java b/syamauchi/src/C052.java
new file mode 100644
index 0000000000000000000000000000000000000000..1260f69e3404d979079716e7a35cc5799430e0bf
--- /dev/null
+++ b/syamauchi/src/C052.java
@@ -0,0 +1,34 @@
+package src;
+
+import java.util.Scanner;
+
+public class C052 {
+  final int verticalResolution; // 縦の画素数
+  final int horizontalResolution; // 横の画素数
+
+  public C052(final int verticalResolution, final int horizontalResolution) {
+    this.verticalResolution = verticalResolution;
+    this.horizontalResolution = horizontalResolution;
+  }
+
+  public static void main(String[] args) {
+    final Scanner sc = new Scanner(System.in);
+    final C052 screen = new C052(sc.nextInt(), sc.nextInt());
+    // 計算して出力
+    System.out.println(screen.redraw(sc.nextInt(), sc.nextInt()));
+    sc.close();
+  }
+
+  // 再描写する画素数の計算
+  public int redraw(final int verticalScroll, final int horizontalScroll) {
+    // スクロールする距離は負の値をとることもあるので絶対値に変換して計算
+
+    // 縦の差分
+    final int verticalDifference = this.horizontalResolution * Math.abs(verticalScroll);
+    // 横の差分
+    final int horizontalDifference = this.verticalResolution * Math.abs(horizontalScroll);
+    // 縦の差分と横の差分の共通部分
+    final int commonScreen = Math.abs(verticalScroll) * Math.abs(horizontalScroll);
+    return verticalDifference + horizontalDifference - commonScreen;
+  }
+}
diff --git a/syamauchi/test/C020Test.java b/syamauchi/test/C020Test.java
new file mode 100644
index 0000000000000000000000000000000000000000..8c036a123c44f456aa4fc3043a395229c6e6da65
--- /dev/null
+++ b/syamauchi/test/C020Test.java
@@ -0,0 +1,27 @@
+package test;
+
+import static org.hamcrest.CoreMatchers.*;
+import static org.hamcrest.MatcherAssert.*;
+import org.junit.Test;
+import src.C020;
+
+public class C020Test {
+
+  @Test
+  public void 残り物の量を取得するテスト1() {
+    C020 sut = new C020("1", "80", "40");
+    float expected = (float) 0.12;
+    float actual = sut.calcUnsold();
+
+    assertThat(actual, is(expected));
+  }
+
+  @Test
+  public void 残り物の量を取得するテスト2() {
+    C020 sut = new C020("10", "31", "52");
+    float expected = (float) 3.312;
+    float actual = sut.calcUnsold();
+
+    assertThat(actual, is(expected));
+  }
+}
diff --git a/syamauchi/test/C052Test.java b/syamauchi/test/C052Test.java
new file mode 100644
index 0000000000000000000000000000000000000000..ad8d26280002a214a7abbfb7f44d1b468a94f1d0
--- /dev/null
+++ b/syamauchi/test/C052Test.java
@@ -0,0 +1,57 @@
+package test;
+
+import static org.hamcrest.CoreMatchers.*;
+import static org.hamcrest.MatcherAssert.*;
+import org.junit.Test;
+import src.C052;
+
+public class C052Test {
+
+  @Test
+  public void 再描画画素数を計算するテスト() {
+    final C052 sut = new C052(240, 180);
+    final int actual = sut.redraw(30, 30);
+    final int expected = 11700;
+
+    assertThat(actual, is(expected));
+  }
+
+  // 解像度の範囲は 1<= verticalResolution, horizontalResolution <=10000
+  @Test
+  public void 解像度がそれぞれ1の時のテスト() {
+    final C052 sut = new C052(1, 1);
+    final int actual = sut.redraw(1, 0);
+    final int expected = 1;
+
+    assertThat(actual, is(expected));
+  }
+
+  @Test
+  public void 解像度がそれぞれ10000の時のテスト() {
+    final C052 sut = new C052(10000, 10000);
+    final int actual = sut.redraw(10000, 0);
+    final int expected = 100000000;
+
+    assertThat(actual, is(expected));
+  }
+
+  // スクロールする距離は負の値をとることもある
+  @Test
+  public void スクロール距離の値が負の時のテスト() {
+    final C052 sut = new C052(10000, 10000);
+    final int actual = sut.redraw(-10000, 0);
+    final int expected = 100000000;
+
+    assertThat(actual, is(expected));
+  }
+
+  // スクロールが行われなければ再描画されない
+  @Test
+  public void 再描画しない時のテスト() {
+    final C052 sut = new C052(10000, 10000);
+    final int actual = sut.redraw(0, 0);
+    final int expected = 0;
+
+    assertThat(actual, is(expected));
+  }
+}