#include <bits/stdc++.h>
#define all(x) (x).begin(),(x).end()
#define pb push_back
#define int long long
using namespace std;
int mod=1e9+7;
vector<int> tree;
void upd(int x, int l, int r, int node, int v){
if(x<l||x>r)return;
if(l==r){
tree[node]+=v;
return;
}
int m=(l+r)/2;
upd(x, l, m, 2*node+1, v);
upd(x, m+1, r, 2*node+2, v);
tree[node]=tree[2*node+1]+tree[2*node+2];
}
int query(int ll, int lr, int l, int r, int node){
if(ll>r||lr<l)return 0;
if(ll<=l&&lr>=r){
return tree[node];
}
int m=(l+r)/2;
return (query(ll, lr, l, m, 2*node+1)+query(ll, lr, m+1, r, 2*node+2))%mod;
}
signed main(){
ios::sync_with_stdio(false);
cin.tie(NULL);
int n; cin >> n;
tree.resize(4*(n+1));
vector<int> d(n+1), x(n+1);
for(int i=1; i<=n; i++){
cin >> d[i] >> x[i];
}
int resp=0;
vector<int> r(n+1);
for(int i=n; i>=1; i--){
if(d[i]!=0){
r[i]=query(i, i+x[i], 1, n, 0);
// for(int j=i; j<=n&&j<=x[i]*d[i]+i; j+=d[i]){
// r[i]=(r[i]+r[j])%mod;
// // cout << i << ": "<<j<<endl;
// }
}
r[i]++;
r[i]%=mod;
upd(i, 1, n, 0, r[i]);
// cout << i << " "<<r[i]<<endl;
// resp=(resp+r[i])%mod;
}
cout << r[1]<<endl;
}
