while True:
    try:
        str_1=input()
        str_2=input()
        c=0
        for i in range(len(str_1)):
            if str_1 [i-c:i+1] in str_2:
                c+=1
        print(c)
    except:
        break
窗口滑动
判断字符串是否在内，增加字符串长度