#include<bits/stdc++.h>
using namespace std;
int main(){
ios_base::sync_with_stdio(false);
int i,j,k,n,m,a,b,c;
cin>>n;
vector<int> x(n),h(n);
for(i=0;i<n;i++){
cin>>x[i]>>h[i];
}
int arr[n][3]; //0=lft,1=st,2=ri
memset(arr,0,sizeof(arr));
/*for(i=0;i<3;i++)
arr[0][i]=1; */
arr[0][0]=1;
arr[0][1]=0;
arr[0][2]=0;
for(i=1;i<n;i++){
if(x[i-1]+h[i]<x[i])
arr[i][0]=max(arr[i-1][0],arr[i-1][1])+1;
arr[i][1]=max({arr[i-1][0],arr[i-1][2],arr[i-1][1]});
if(i+1<n && x[i]+h[i]<x[i+1])
arr[i][2]=max({arr[i-1][0],arr[i-1][1],arr[i-1][2]})+1;
}
if(n-2>=0)
arr[n-1][2]=max({arr[n-2][0],arr[n-2][1],arr[n-2][2]})+1;
cout<<max({arr[n-1][0],arr[n-1][1],arr[n-1][2]})<<"\n";
/*for(i=0;i<3;i++, cout<<"\n"){
for(j=0;j<n;j++)
cout<<arr[j][i]<<" ";
}*/
return 0;
}
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