#include <bits/stdc++.h>
using namespace std;

const int N = 110; 
int n, m, u, v;
bool t, vis[N];
vector<int> G[N];

void Circle(int beg, int p) {
	for(auto i: G[p]) {
		if(vis[i]) {
			t = 1; return;
		}
		vis[i] = 1;
		Circle(beg, i);
	}
}

int main() {
	scanf("%d%d", &n, &m);
	for(int i = 1; i <= m; i++) {
		scanf("%d%d", &u, &v);
		G[u].push_back(v);
	}
	for(int i = 1; i <= n; i++) {
		memset(vis, 0, sizeof(vis));
		vis[i] = 1;
		Circle(i, i);
	}
	if(t) printf("has circle\n");
	else printf("has not circle\n");
	return 0;
}