Info Soal?

// Tested by zydhanlinnar11 on May 31, 2022
#include <iostream>
#include <vector>
#include <algorithm>
#include <set>
#include <cassert>
using namespace std;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef set<int> si;
typedef vector<si> vsi;

bool dfs(vi &clr, vsi &adjList, int n, int u, int depth) {
    if(clr[u] >= 1) return depth == n;
    clr[u] = 1;
    bool res = false;
    for(auto &v: adjList[u]) res |= dfs(clr, adjList, n, v, depth + 1);
    clr[u] = 0;
    return res;
}

int main() {
    #ifdef ZYD_WSL
        freopen("/home/zydhanlinnar11/prakfinal-qa/in", "r", stdin);
    #endif
    int n, m; cin>>n>>m;
    assert(0 <= n && n <= 10);
    assert(0 <= m && m <= 45);
    vvi adjList(n); vsi adjList2(n);
    for(int i=0; i<m; i++) {
        int u, v; cin>>u>>v;
        assert(0 <= u && u < n);
        assert(0 <= v && v < n);
        adjList[u].push_back(v);
        adjList[v].push_back(u);
    }
    for(int i=0; i<n; i++)
        for(auto &j: adjList[i])
            for(auto &v: adjList[j]) {
                if(v == i) continue;
                adjList2[i].insert(v); adjList2[v].insert(i);
            }
    bool ans = false;
    for(int i=0; i<n; i++) {
        vi clr(n, 0);
        ans |= dfs(clr, adjList2, n, i, 0);
    }
    cout<<(ans ? "YES" : "NO")<<"\n";
}