#include <iostream>
#include <vector>
#include <map>
#include <set>
#include <queue>
#include <algorithm>
#include <iomanip>
#include <cassert>
using namespace std;

#define GET_ARG(a,b,c,F,...) F
#define REP3(i,s,e) for (i = s; i <= e; i++)
#define REP2(i,n) REP3 (i,0,(int)(n)-1)
#define REP(...) GET_ARG (__VA_ARGS__,REP3,REP2) (__VA_ARGS__)
#define RREP3(i,s,e) for (i = s; i >= e; i--)
#define RREP2(i,n) RREP3 (i,(int)(n)-1,0)
#define RREP(...) GET_ARG (__VA_ARGS__,RREP3,RREP2) (__VA_ARGS__)
#define DEBUG(x) cerr << #x ": " << x << endl

vector<int> e[20000];
int color[20000];
bool dp[1<<4][20000];

int main(void) {
    int i, j, n, m;
    scanf("%d%d",&n,&m);
    REP (i,m) {
        int a, b;
        scanf("%d%d",&a,&b);
        a--; b--;
        e[a].push_back(b);
        e[b].push_back(a);
    }
    int loops = 200;
    while (loops--) {
        REP (i,n) color[i] = rand() % 4;
        REP (i,1<<4) REP (j,n) dp[i][j] = false;
        for (auto x: e[0]) {
            dp[1<<color[x]][x] = true;
        }
        REP (i,1<<4) REP (j,1,n-1) for (auto x: e[j]) if (x != 0 && !(i&1<<color[x])) {
            dp[i|1<<color[x]][x] |= dp[i][j];
        }
        for (auto x: e[0]) if (dp[(1<<4)-1][x]) {
            puts("YES");
            return 0;
        }
    }
    puts("NO");
    return 0;
}