Connect cities

inp = input().split(" ")

num_cities, num_roads = (int(inp[0]), int(inp[1]))

cities = [[] for _ in range(num_cities)]

for i in range(num_roads):
    inp = input().split(" ")
    a, b = (int(inp[0]), int(inp[1]))

    cities[a - 1].append(b - 1)
    # cities[b - 1].append(a - 1)

visited = [False for _ in range(num_cities)]
components = []


def search_city(city_index):
    if visited[city_index]:
        return

    visited[city_index] = True
    for neighbor in cities[city_index]:
        search_city(neighbor)


for city_index in range(len(cities)):
    if visited[city_index]:
        continue

    components.append(city_index + 1)
    search_city(city_index)


if len(components) > 0:
    a = components[0]
    print(len(components) - 1)

    for i in range(1, len(components)):
        print(a, components[i])
else:
    print(0)

Test 1

Verdict: ACCEPTED

Test 2

Verdict: WRONG ANSWER

Test 3

Verdict: WRONG ANSWER

Test 4

Verdict: WRONG ANSWER

Test 5

Verdict: WRONG ANSWER

Test 6

Verdict: WRONG ANSWER

Test 7

Verdict: WRONG ANSWER

Test 8

Verdict: WRONG ANSWER

Test 9

Verdict: WRONG ANSWER

Test 10

Verdict: WRONG ANSWER

Test 11

Verdict: ACCEPTED

Test 12

Verdict: ACCEPTED