#include<stdio.h>
#include<string.h>
#include<queue>
#include<algorithm>
using namespace std;#define MAXN 100 + 5
#define INF 0xfffffffint n, m, f;
int flow[MAXN][MAXN];
int Edge[MAXN][MAXN];
int pre[MAXN];
bool mark[MAXN];//最大流模版，不解释了。
void max_flow(int u, int v)
{f = 0;while(1) {memset(mark, 0, sizeof(mark));memset(pre, 0, sizeof(pre));queue<int> Q;mark[u] = 1;Q.push(u);while( !Q.empty() ) {int cnt = Q.front();Q.pop();if(cnt == v) {break;}for(int i = 0; i < n * 2; i++) {if(!mark[i] && flow[cnt][i] > 0) {mark[i] = 1;Q.push(i);pre[i] = cnt;}}}if( !mark[v]) {break;}int minx = INF;for(int i = v; i != u; i = pre[i]) {minx = min(flow[pre[i]][i], minx);}for(int i = v; i != u; i = pre[i]) {flow[pre[i]][i] -= minx;flow[i][pre[i]] += minx;}f += minx;}
}int main()
{while(scanf("%d %d%*c", &n, &m) != EOF) {memset(Edge, 0, sizeof(Edge));int k = -1; //k为源点。if(n == 1 && m == 0) {printf("1\n");continue;}if(m == 0) {printf("0\n");continue;}for(int i = 0; i < m; i++) {//注意输入的格式，因为这快儿RE了很多次。while(getchar()!='(');int u, v;scanf("%d,%d)", &u, &v);//图的转换，方法上面以给出。Edge[u][n + u] = 1;Edge[v][n + v] = 1;Edge[n + u][v] = INF;Edge[n + v][u] = INF;if( k == -1) {k = n + u;}}int ans = INF;//枚举0-n的点到源点的最大流，ans为其中最小的。for(int i = 0; i < n; i++) {if(i + n == k) {continue;}for(int j = 0; j < 2 * n; j++) {for(int t = 0; t < 2 * n; t++) {flow[j][t] = Edge[j][t];}}max_flow(k, i);ans = min(f, ans);}//当ans == INF说明图是强连通的，所以要去掉所有的点。if(ans == INF) {printf("%d\n", n);} else {printf("%d\n", ans);}}return 0;
}