n, m = list(map(int,input().split())) values = [] for i in range(n): values.append(input()) values = sorted(values) for i in range(m): str1, str2 = input().split() for i, j in enumerate(values): if j[0:len(str1)] == str1 and j[0:len(str2)] != str2: print(j) del values[i] break else: print(-1)