View Code of Problem 6

number = int(input())
rest = []
while number:
    arry_number = int(input())
    arry_rest = [""]
    while arry_number:
        a, b = input().split()
        # arry_rest.append(a)
        # arry_rest.append(b)
        if int(b) - int(a) == 1:
            arry_rest[0] = "YES"
            # print(arry_rest)
        else:
            arry_rest.append("NO")
        arry_number = arry_number - 1
    rest.append(arry_rest[-1])
    number = number - 1

# print(rest)
for _ in rest:
    print(_)