#include "bits/stdc++.h"
using namespace std;
#define FOR(i,j,k) for(int (i)=(j);(i)<(int)(k);++(i))
#define rep(i,j) FOR(i,0,j)
#define each(x,y) for(auto &(x):(y))
#define mp make_pair
#define all(x) (x).begin(),(x).end()
#define debug(x) cout<<#x<<": "<<(x)<<endl
#define smax(x,y) (x)=max((x),(y))
#define smin(x,y) (x)=min((x),(y))
#define MEM(x,y) memset((x),(y),sizeof (x))
#define sz(x) (int)(x).size()
typedef long long ll;
typedef pair<int, int> pii;
typedef vector<int> vi;
typedef vector<ll> vll;

const int N_MAX = 20001;
int N, M, C[N_MAX], vis[N_MAX][1 << 5], ok = 0;
vi G[N_MAX];

void dfs(int u, int S){
    if(vis[u][S]++)return;

    if(S == (1 << 5) - 1){
        each(v, G[u])if(v == 0)ok = 1;
        return;
    }
    each(v, G[u]) if(!(C[v]&S)) dfs(v, S | C[v]);
}

int main(){
    cin >> N >> M;
    rep(i, M){
        int A, B;
        scanf("%d%d", &A, &B);
        G[--A].push_back(--B);
        G[B].push_back(A);
    }

    rep(iter, 1000){
        MEM(vis, 0);
        rep(i, N)C[i] = 1<<(rand()%5);
        dfs(0, C[0]);
    }

    puts(ok ? "YES" : "NO");
}