[SWEA] 비밀번호

T = 10
for TC in range(T):
    str1, str2 = input().split()
    stack = []
    for i in range(1):
        stack.append(str2[0])
        for j in range(1, len(str2)):
            if len(stack) > 0:
                pop = stack[-1]
                if pop == str2[j]:
                    stack.pop(-1)
                else:
                    stack.append(str2[j])
            else:
                stack.append(str2[j])
    print('#{} '.format(TC+1), end = '')
    for i in stack:
        print(i, end = '')
    print()