yukicoder contest 299 (BANNED CONTEST) 参戦記
A 1543 [Cherry 2nd Tune A] これがプログラミングなのね
cに従って比較をするだけ.
S, T, c = input().split()
S = int(S)
T = int(T)
if c == '<':
    result = S < T
elif c == '>':
    result = S > T
elif c == '=':
    result = S == T
if result:
    print('YES')
else:
    print('NO')
B 1544 [Cherry 2nd Tune C] Synchroscope
O(NM) が実行可能な範囲なので、愚直に比較すればいいだけ.
N, M = map(int, input().split())
A = list(map(int, input().split()))
B = list(map(int, input().split()))
for i in range(N * M):
    if A[i % N] != B[i % M]:
        continue
    print(i + 1)
    break
else:
    print(-1)