文件目录

#include <bits/stdc++.h>
using namespace std;
int a1[105][105], a2[105][105];
bool b[105];
int n, m, x, y;
int num = 0;
void dfs(int point, int a[105][105])
{
    num++;
    b[point] = true;
    for (int i = 1; i <= n; i++)
        if (a[point][i] && !b[i])
            dfs(i, a);
}
int main()
{
    cin >> n >> m;
    while (m--)
    {
        cin >> x >> y;
        a1[x][y] = 1;
        a2[y][x] = 1;
    }
    int ans = 0;
    for (int i = 1; i <= n; i++)
    {
        num = 0;
        memset(b, 0, sizeof(b));
        dfs(i, a1);
        if (num > (n + 1) / 2)
            ans++;
    }
    for (int i = 1; i <= n; i++)
    {
        num = 0;
        memset(b, 0, sizeof(b));
        dfs(i, a2);
        if (num > (n + 1) / 2)
            ans++;
    }
    cout << ans;
    return 0;
}