刚学的Python做这题，前三个wa，后两个过了，不太懂

per = int(input())
str = input()


def op(typ, str, strn='', s=0, stp=0):
    if (typ == 1):
        str = str + strn
    elif (typ == 2):
        str = str[s:s + stp]
    elif (typ == 3):
        strnn = str
        str = strnn[:s]
        str += strn
        str += strnn[s:]
    else:
        print(str.find(strn))
    return str


for i in range(per):
    sk = input()
    skk = sk.split()
    if (skk[0] == '1'):
        str = op(int(skk[0]), str, skk[1])
        print(str)
    elif (skk[0] == '2'):
        str = op(int(skk[0]), str, '', int(skk[1]), int(skk[2]))
        print(str)
    elif (skk[0] == '3'):
        str = op(int(skk[0]), str, skk[2], int(skk[1]))
        print(str)
    else:
        str = op(int(skk[0]), str, skk[1])