add ABC006 A, B

Author: IsHYuhi

ABC/ABC006/A.py

@@ -0,0 +1,7 @@
+N = input()
+if '3' in list(N):
+    print('YES')
+elif int(N)%3 ==0:
+    print('YES')
+else:
+    print('NO')

ABC/ABC006/B.py

@@ -0,0 +1,27 @@
+#pypy
+Sequence = [float('inf') for _ in range(1000000+1)]
+Sequence[0] = 0
+Sequence[1] = 0
+Sequence[2] = 0
+Sequence[3] = 1
+
+def tribonacci(n):
+    if Sequence[n] != float('inf'):
+        return Sequence[n]
+    return tribonacci(n-1) + tribonacci(n-2) + tribonacci(n-3)
+
+def tribonacci_h(n):
+    if n == 1:
+        return 0
+    elif n ==2:
+        return 0
+    elif n ==3:
+        return 1
+
+    for i in range(4, n+1):
+        Sequence[i] = (Sequence[i-3] + Sequence[i-2] + Sequence[i-1])%10007
+    return Sequence[n]
+
+
+n = int(input())
+print(tribonacci_h(n)%10007)