CUUCHUOI C++

#include <bits/stdc++.h>
using namespace std;
int n,s,x,i,p1,p2,p3,gia;
void nhap()
{
    //scanf("%d\n %d",&n,&x);
    cin>>n>>x;
}
void xuli()
{
    s=0;
    for(int i=1;i<=n;i++)
    {
        //scanf("%d %d",&p1,&p2);
        cin>>p1>>p2;
        if(abs(p1-p2)<=x) gia=max(p1,p2);
        else
        {
            //scanf("%d",&p3);
            cin>>p3;
            gia=p3;
        }
        s=s+gia;
    }
    printf("%d",s);
}
int main()
{
    freopen("cuuchuoi.inp","r",stdin);
    freopen("cuuchuoi.out","w",stdout);
    nhap();
    xuli();
}