#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef vector<int> vi;
typedef vector<ll> vl;
typedef complex<double> P;
typedef pair<int,int> pii;
#define REP(i,n) for(ll i=0;i<n;++i)
#define REPR(i,n) for(ll i=1;i<n;++i)
#define FOR(i,a,b) for(ll i=a;i<b;++i)

#define DEBUG(x) cout<<#x<<": "<<x<<endl
#define DEBUG_VEC(v) cout<<#v<<":";REP(i,v.size())cout<<" "<<v[i];cout<<endl
#define ALL(a) (a).begin(),(a).end()

#define MOD (ll)(1e9+7)
#define ADD(a,b) a=((a)+(b))%MOD
#define FIX(a) ((a)%MOD+MOD)%MOD

int main(){
  // counting eulerian circuit
  int n,m;
  cin >> n >> m;
  vector<vi> G(n,vi(n,1));
  REP(i,m){
    int a,b;
    cin >> a >> b;
    --a;--b;
    G[a][b] = 0;
  }
  int beg=-1,end=-1;
  REP(i,n){
    int in = 0, out = 0;
    REP(j,n){
      if(G[i][j]==1)in += 1;
      if(G[j][i]==1)out += 1;
    }
    if(in==out)continue;
    if(in+1==out){
      if(beg==-1){
        beg = i;
        continue;
      }
    }
    if(in==out+1){
      if(end==-1){
        end = i;
        continue;
      }
    }
    cout << 0 << endl;
    return 0;
  }
  if(n*n==m){
    cout << 1 << endl;
    return 0;
  }
  cout << n*n << endl;
  return 0;
}