codeforces 15A. Cottage Village

#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <ctype.h>
#include <math.h>
#include <stack>
#include <queue>
#include <map>
#include <set>
#include <vector>
#include <string>
#include <iostream>
#include <algorithm>
using namespace std;
#define ll long long
#define ls rt<<1
#define rs ls1
#define lson l,mid,ls
#define rson mid+1,r,rs
#define middle (l+r)>>1
#define eps (1e-6)
#define clr_all(x,c) memset(x,c,sizeof(x))
#define clr(x,c,n) memset(x,c,sizeof(x[0])*(n+1))
#define MOD 1000000007
#define inf 100000007
#define pi acos(-1.0)
#define M 2000+5
int n,t,cn,a[M];
int main(){
    int T,i,j,k;
    while(~scanf("%d %d",&n,&t)){
for(i=0;i<n;i++){
scanf("%d %d",&j,&k);
a[i*2]=j*2+k;
a[i*2+1]=j*2-k;
}
sort(a,a+2*n);
n*=2;
t*=2;
cn=2;
for(i=1;i<n;i+=2){
if(a[i+1]-a[i]>t)cn+=2;
else if(a[i+1]-a[i]==t)cn++;
}
printf("%d\n",cn);
}
    return 0;
}