#include <bits/stdc++.h>
int N,c1[500009],c2[500009],kk,sg[500009],tf[500009];
struct n_t{
    int x,y,c;
} f[500009];
bool cmp(n_t a,n_t b) {
    return a.x+a.y<b.x+b.y;
}
#define lb(x) ((x)&(-(x)))
void up(int p) {
    while(p<=N) {
        sg[p]++;
        p+=lb(p);
    }
}
inline int qr(int p) {
    int as=0;
    while(p) {
        as+=sg[p];
        p-=lb(p);
    }
    return as;
}
long long cl() {
    std::sort(f+1,f+N+1,cmp);
    memset(c1,0,sizeof(c1));
    memset(c2,0,sizeof(c2));
    for(int i=1;i<=N;i++) {
        tf[i]=f[i].x-f[i].y;
    }
    std::sort(tf+1,tf+N+1);
    for(int i=1;i<=N;i++) {
        f[i].c=std::lower_bound(tf+1,tf+N+1,f[i].x-f[i].y)-tf;
    }
    memset(sg,0,sizeof(sg));
    int p=0;
    for(int i=1;i<=N;i++) {
        while(p<N&&f[p+1].x+f[p+1].y<f[i].x+f[i].y) {
            p++;
            up(f[p].c);
        }
        c1[i]=qr(f[i].c-1);
    }
    memset(sg,0,sizeof(sg));
    long long ans=0;
    p=N+1;
    for(int i=N;i>=1;i--) {
        while(p>1&&f[p-1].x+f[p-1].y>f[i].x+f[i].y) {
            p--;
            up(N-f[p].c+1);
        }
        c2[i]=qr(N-f[i].c);
        ans+=1ll*c1[i]*c2[i];
    }
    return ans;
}
signed main(void) {
    scanf("%d",&N);
    for(int i=1;i<=N;i++) {
        scanf("%d %d",&f[i].x,&f[i].y);
    }
    long long ans=1ll*N*(N-1)*(N-2)/6;
    ans-=cl();
    for(int i=1;i<=N;i++) std::swap(f[i].x,f[i].y);
    ans-=cl();
    printf("%lld",ans);
}