#include <iostream>
using namespace std;
int c[1000000];
int main() {
	int a,b,sum=0,max=-1,count=0,s=0;
	cin>>a>>b;
	for (int i=0;i<a;i++){
		cin>>sum>>max>>c[i];
	if (i==1||i==2){
		count+=c[i];}
	}
cout<<count<<endl;

	return 0;

}