#include <bits/stdc++.h>
using namespace std;
#define fi first
#define se second
int main() {
    int n,m;
    cin>>n>>m;
    int ans=0;
    for (int i = 0; i < m; ++i)
    {
        int b,t;
        cin>>b>>t;
        if(b==0||t==0) continue;
        ans += (b!=t);
    }
    cout <<ans<<endl;
}
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