// Author: Teoman Ata Korkmaz
#include <bits/stdc++.h>
#define int int_fast64_t
using namespace std;
constexpr int N=100005;
constexpr int MOD=1e9+7;
///////////////////////////////////////////////////////////
int n,d[N],x[N],v[N],ans;
signed main(void){
cin>>n;
for(int i=0;i<n;i++)cin>>d[i]>>x[i];
v[0]=1;
int cnt=0;
priority_queue<pair<int,int>> q;
for(int i=0;i<n;i++){
while(q.size() && -q.top().first<i){
cnt-=q.top().second-MOD;
cnt%=MOD;
q.pop();
}
v[i]=(v[i]+cnt)%MOD;
ans=(ans+v[i])%MOD;
q.push({-i-x[i],v[i]});
cnt+=v[i];
}
cout<<ans<<endl;
}
