#include <iostream>
using namespace std;
int main(){
    int a = 0;
    int x = 0;
    int c = 0;
    cin >> a >> x;
    int o[a];
    int y[x];
    for(int i = 0;i<a;i++)
    {
        cin >> o[i] >> y[i];
        if(y[i]==1)
		{
			c++;
		}
    }
    cout <<c;
	return 0;
}