diff --git a/knoda/src/A052_ClimbingStairs.java b/knoda/src/A052_ClimbingStairs.java
new file mode 100644
index 0000000000000000000000000000000000000000..f4ca1ed47eba80e3247cb6177e13a1a03975b97c
--- /dev/null
+++ b/knoda/src/A052_ClimbingStairs.java
@@ -0,0 +1,45 @@
+package hellojunit;
+
+import java.util.HashSet;
+import java.util.Scanner;
+import java.util.Set;
+
+public class A052_ClimbingStairs {
+
+	public static void main(String[] args) {
+		final Scanner scan = new Scanner(System.in);
+		final int stairsNum = scan.nextInt();    // 階段の数
+		final int skipStepNumA = scan.nextInt(); // A段飛ばし
+		final int skipStepNumB = scan.nextInt(); // B段飛ばし
+		scan.close();
+		ClimbingStairs climbingStairs = new ClimbingStairs();
+		// 未到達の段数を取得する
+		System.out.println(climbingStairs.getNotStepStairs(stairsNum, skipStepNumA, skipStepNumB));
+	}
+
+}
+
+class ClimbingStairs {
+	
+	/**
+	 * 未到達の段数を取得するメソッド
+	 * @param stairsNum : 階段の段数
+	 * @param skipStepNumA : A段飛ばし
+	 * @param skipStepNumB : B段飛ばし
+	 * @return stairsNum - ableSteps : 未到達の段数
+	 */
+	public int getNotStepStairs(final int stairsNum, final int skipStepNumA, final int skipStepNumB) {
+		Set<Integer> steps = new HashSet<Integer>(stairsNum);
+		steps.add(0);
+		int ableSteps = 0;
+		for (int i = 0; i < stairsNum; i++) {
+			if (steps.contains(i)) {
+				ableSteps++;
+				steps.add(i + skipStepNumA);
+				steps.add(i + skipStepNumB);
+			}
+		}
+		
+		return stairsNum - ableSteps;
+	}
+}
diff --git a/knoda/test/A052_ClimbingStairsTest.java b/knoda/test/A052_ClimbingStairsTest.java
new file mode 100644
index 0000000000000000000000000000000000000000..3c198747f1f5faed8b847f94032a2420739c7890
--- /dev/null
+++ b/knoda/test/A052_ClimbingStairsTest.java
@@ -0,0 +1,76 @@
+package hellojunit;
+
+import static org.hamcrest.CoreMatchers.*;
+import static org.junit.Assert.*;
+
+import org.junit.Test;
+
+public class A052_ClimbingStairsTest {
+
+	@Test
+	public void 階段の段数が1段のときのテスト() {
+		final int stairsNum = 1;
+		final int skipStepNumA = 3;
+		final int skipStepNumB = 4;
+		ClimbingStairs climbingStairs = new ClimbingStairs();
+		final int actual = climbingStairs.getNotStepStairs(stairsNum, skipStepNumA, skipStepNumB);
+		final int expected = 0;
+		assertThat(actual, is(expected));
+	}
+	
+	@Test
+	public void 階段の段数が200000段のときのテスト() {
+		final int stairsNum = 200000;
+		final int skipStepNumA = 90;
+		final int skipStepNumB = 100;
+		ClimbingStairs climbingStairs = new ClimbingStairs();
+		final int actual = climbingStairs.getNotStepStairs(stairsNum, skipStepNumA, skipStepNumB);
+		final int expected = 180036;
+		assertThat(actual, is(expected));
+	}
+	
+	@Test
+	public void 基本テスト1() {
+		final int stairsNum = 8;
+		final int skipStepNumA = 3;
+		final int skipStepNumB = 5;
+		ClimbingStairs climbingStairs = new ClimbingStairs();
+		final int actual = climbingStairs.getNotStepStairs(stairsNum, skipStepNumA, skipStepNumB);
+		final int expected = 4;
+		assertThat(actual, is(expected));
+	}
+	
+	@Test
+	public void 基本テスト2() {
+		final int stairsNum = 10;
+		final int skipStepNumA = 2;
+		final int skipStepNumB = 4;
+		ClimbingStairs climbingStairs = new ClimbingStairs();
+		final int actual = climbingStairs.getNotStepStairs(stairsNum, skipStepNumA, skipStepNumB);
+		final int expected = 5;
+		assertThat(actual, is(expected));
+	}
+	
+	@Test
+	public void 基本テスト3() {
+		final int stairsNum = 15;
+		final int skipStepNumA = 4;
+		final int skipStepNumB = 6;
+		ClimbingStairs climbingStairs = new ClimbingStairs();
+		final int actual = climbingStairs.getNotStepStairs(stairsNum, skipStepNumA, skipStepNumB);
+		final int expected = 8;
+		assertThat(actual, is(expected));
+	}
+	
+	@Test
+	public void 基本テスト4() {
+		final int stairsNum = 7;
+		final int skipStepNumA = 3;
+		final int skipStepNumB = 5;
+		ClimbingStairs climbingStairs = new ClimbingStairs();
+		final int actual = climbingStairs.getNotStepStairs(stairsNum, skipStepNumA, skipStepNumB);
+		final int expected = 3;
+		assertThat(actual, is(expected));
+	}
+
+}