#include <bits/stdc++.h>
using namespace std;
const int mod = 1e9 + 7;
const int MAXN = 100355;
int suff[350][MAXN], ans[MAXN];
int main(){
ios_base::sync_with_stdio(false);
cin.tie(0); cout.tie(0);
int nums; cin >> nums;
vector<int> step(nums + 1), stop(nums + 1);
for (int i = 1; i <= nums; i++){
int amt; cin >> step[i] >> amt;
if (step[i] != 0){
amt = min(amt, (nums - i) / step[i]);
stop[i] = i + amt * step[i];
}
}
int bsz = 330;
for (int i = nums; i >= 1; i--){
ans[i] = 1;
int ssz = step[i];
if (ssz > bsz){
for (int x = stop[i]; x > i; x -= ssz) ans[i] = (ans[i] + ans[x]) % mod;
}
else if (ssz != 0){
ans[i] = (ans[i] + suff[ssz][i + ssz] - suff[ssz][stop[i] + ssz] + mod) % mod;
}
for (int x = 1; x <= bsz; x++) suff[x][i] = (suff[x][i + x] + ans[i]) % mod;
}
cout << ans[1];
}
