只过了前三个样例，求解 我真是算盘珠子，拨一拨动一动```python def work1(str1, str2): return str1 + str2

def work2(str1, n, m): return str1[n:m + n]

def work3(str1, n, str2): m = eval(n) a = [i for i in str1] b = [i for i in str2] for i in range(len(b)): a.insert(m, b[i]) m += 1 str3 = ''.join(a) return str3

def work4(str1, str2): a = [i for i in str1] for i in range(len(str1) - len(str2)): flag = 0 if a[i] == str2[0]: for j in range(0, len(str2)): if a[j + i] != str2[j]: flag = 1 break else: continue if flag == 0: return i return -1

n = eval(input()) str1 = input().rstrip('\r') words = [i for i in str1] for i in range(n): a = [] a = input().split() if a[0] == '1': str1 = work1(str1, a[1]) print(str1) elif a[0] == '2': str1 = work2(str1, int(a[1]), int(a[2])) print(str1) elif a[0] == '3': str1 = work3(str1, a[1], a[2]) print(str1) elif a[0] == '4': num = work4(str1, a[1]) print(num)