Snakeless path

#include <bits/stdc++.h>
using namespace std;

#define rep(i, a, b) for(int i = a; i < (b); ++i)
#define all(x) begin(x), end(x)
#define sz(x) (int)(x).size()
#define int long long
typedef pair<int, int> pii;
typedef vector<int> vi;

vector<vector<int>> adj;

signed main() {
	cin.tie(0)->sync_with_stdio(0);
	cin.exceptions(cin.failbit);

	int n, m;
	cin >> n >> m;
	adj.resize(n);

	rep(i, 0, m){
	    int a, b;
	    cin >> a >> b;
        adj[a-1].push_back(b-1);
        adj[b-1].push_back(a-1);
	}

	vector<int> sol;
	sol.push_back(1);
	rep(i, 0, n){
	    if (adj[i].size() == 0){
	        sol.push_back(i+1);
	        break;
	    }
	}

	if (sol.size() == 2){
	    sol.push_back(n);
	} else {
	    cout << 0;
	    return 0;
	}

    for (int i : sol){
        cout << i << " ";
    }
	return 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: ACCEPTED

Test 7

Verdict: ACCEPTED

Test 8

Verdict: WRONG ANSWER

Test 9

Verdict: ACCEPTED

Test 10

Verdict: WRONG ANSWER

Test 11

Verdict: WRONG ANSWER

Test 12

Verdict: WRONG ANSWER

Test 13

Verdict: WRONG ANSWER

Test 14

Verdict: ACCEPTED

Test 15

Verdict: ACCEPTED

Test 16

Verdict: WRONG ANSWER

Test 17

Verdict: ACCEPTED

Test 18

Verdict: ACCEPTED

Test 19

Verdict: ACCEPTED

Test 20

Verdict: WRONG ANSWER

Test 21

Verdict: WRONG ANSWER

Test 22

Verdict: WRONG ANSWER

Test 23

Verdict: WRONG ANSWER

Test 24

Verdict: ACCEPTED

Test 25

Verdict: ACCEPTED

Test 26

Verdict: WRONG ANSWER

Test 27

Verdict: ACCEPTED

Test 28

Verdict: ACCEPTED

Test 29

Verdict: ACCEPTED

Test 30

Verdict: WRONG ANSWER

Test 31

Verdict: WRONG ANSWER

Test 32

Verdict: WRONG ANSWER

Test 33

Verdict: WRONG ANSWER

Test 34

Verdict: ACCEPTED

Test 35

Verdict: ACCEPTED

Test 36

Verdict: WRONG ANSWER

Test 37

Verdict: ACCEPTED

Test 38

Verdict: ACCEPTED

Test 39

Verdict: ACCEPTED

Test 40

Verdict: WRONG ANSWER

Test 41

Verdict: WRONG ANSWER

Test 42

Verdict: WRONG ANSWER

Test 43

Verdict: WRONG ANSWER

Test 44

Verdict: ACCEPTED

Test 45

Verdict: ACCEPTED

Test 46

Verdict: WRONG ANSWER

Test 47

Verdict: ACCEPTED

Test 48

Verdict: ACCEPTED

Test 49

Verdict: ACCEPTED

Test 50

Verdict: WRONG ANSWER

Test 51

Verdict: WRONG ANSWER

Test 52

Verdict: WRONG ANSWER

Test 53

Verdict: WRONG ANSWER

Test 54

Verdict: WRONG ANSWER

Test 55

Verdict: ACCEPTED

Test 56

Verdict: WRONG ANSWER

Test 57

Verdict: ACCEPTED

Test 58

Verdict: WRONG ANSWER

Test 59

Verdict: ACCEPTED

Test 60

Verdict: WRONG ANSWER

Test 61

Verdict: ACCEPTED

Test 62

Verdict: ACCEPTED

Test 63

Verdict: WRONG ANSWER

Test 64

Verdict: WRONG ANSWER

Test 65

Verdict: WRONG ANSWER

Test 66

Verdict: ACCEPTED

Test 67

Verdict: ACCEPTED

Test 68

Verdict: WRONG ANSWER

Test 69

Verdict: ACCEPTED

Test 70

Verdict: WRONG ANSWER

Test 71

Verdict: WRONG ANSWER

Test 72

Verdict: WRONG ANSWER

Test 73

Verdict: WRONG ANSWER

Test 74

Verdict: WRONG ANSWER

Test 75

Verdict: ACCEPTED

Test 76

Verdict: WRONG ANSWER

Test 77

Verdict: ACCEPTED

Test 78

Verdict: WRONG ANSWER

Test 79

Verdict: ACCEPTED

Test 80

Verdict: WRONG ANSWER

Test 81

Verdict: ACCEPTED

Test 82

Verdict: ACCEPTED

Test 83

Verdict: WRONG ANSWER

Test 84

Verdict: WRONG ANSWER

Test 85

Verdict: WRONG ANSWER

Test 86

Verdict: ACCEPTED

Test 87

Verdict: ACCEPTED

Test 88

Verdict: WRONG ANSWER

Test 89

Verdict: ACCEPTED