#include <bits/stdc++.h>

using namespace std;

int n,m;
bool viz[100003];
vector<int>L[100003];

void Citire()
{
    int x,y;
    ifstream fin ("date.in");
    fin>>n>>m;
    for(int i=1;i<=m;i++)
    {
       fin>>x>>y;
       L[x].push_back(y);
       L[y].push_back(x);
    }
    fin.close();
}
bool exista_ciclu = false;

void DFS(int x, int t)
{
    viz[x] = true;
    unsigned int i;
    for(i=0;i<L[x].size();++i)
    {
        int y = L[x][i];
        if(y!=t)
        {
            if(viz[y]==true)
                exista_ciclu = true;
            else
                DFS(y,x);
        }
    }
}

int main()
{
    Citire();
    for(int i=1;i<=n;++i)
        if(!viz[i])
            DFS(i,0);
    cout<<exista_ciclu<<"\n";
    return 0;
}