Connect cities

import sys




#build adjacecny and get input
input_data = sys.stdin.read().split()#get whole input data at once
n_cities = int(input_data[0])
n_roads = int(input_data[1])

adj = [[] for _ in range(n_cities+1)] #list of lists : eg for element 1 : [4,8,2]

k = 2
for _ in range(n_roads):
    a = int(input_data[k])
    b = int(input_data[k+1])
    adj[a].append(b)
    adj[b].append(a)
    k+=2


components = []
visited = [0]*(n_cities+1) 

for i in range(1,n_cities+1):
    if not visited[i]:

        visited[i]=1
        comp= []
        stack = [i]
        while(stack):
            current = stack.pop()
            comp.append(current)
            for neighbor in adj[current]:
                if not visited[neighbor]:
                    visited[neighbor] = 1
                    stack.append(neighbor)
        components.append(comp)#add our comp to the list of components

#print(components)
#now we have our connected components

missing_roads = len(components) -1
new_roads = []
if missing_roads >0 :
    new_roads = []
    for i in range(missing_roads):
        new_roads.append([components[i][0],components[i+1][0]])

print(len(new_roads))
for r in new_roads:
    print(r)

Test 1

Verdict: WRONG ANSWER

Test 2

Verdict: WRONG ANSWER

Test 3

Verdict: ACCEPTED

Test 4

Verdict: WRONG ANSWER

Test 5

Verdict: ACCEPTED

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: WRONG ANSWER

Test 12

Verdict: WRONG ANSWER