소스 코드 제출

# a = input()
# b = 0
# for i in a:
#     if i in 'ABC':
#         b += 3
#     elif i in 'DEF':
#         b += 4
#     elif i in 'GHI':
#         b += 5
#     elif i in 'JKL':
#         b += 6
#     elif i in 'MNO':
#         b += 7
#     elif i in 'POQRS':
#         b += 8
#     elif i in 'TUV':
#         b += 9
#     elif i in 'WXYZ':
#         b += 10
# print(b)

# a = input().split()
# print(len(a))

a = int(input())
for i in range(a):
    x, y = input().split()
    x = int(x)
    for j in range(len(y)):
        print(y[j]*x, end='')