#include <bits/stdc++.h>
#include <vector>
#include <iostream>
using namespace std;
#define ll long long
#define mod 1000000007
ll calculateTotal(vector<ll> &dp){
ll total = 0;
for(auto entry : dp){
total += entry;
total %= mod;
}
return total;
}
ll processPrev(unordered_map<ll, unordered_map<ll, ll> > &pending, ll index) {
ll answer = 0;
for(auto& entry : pending){
ll d = entry.first;
auto& countMap = entry.second;
if(countMap.find(index % d) != countMap.end()){
answer += countMap[index % d];
answer %= mod;
}
}
return answer;
}
void addNext(ll d, ll x, ll index, ll count, ll n, unordered_map<ll, unordered_map<ll, ll> > &pending,
unordered_map<ll, vector<vector<ll> > > &ending)
{
ll i = index % d;
vector<ll> end = {d, i, count};
ll endIndex = index + d * x;
if(endIndex > n){
endIndex = n;
}
if(pending.find(d) == pending.end()){
pending[d] = unordered_map<ll, ll>();
}
pending[d][i] += count;
if(ending.find(endIndex) == ending.end()){
ending[endIndex] = vector<vector<ll> >();
}
ending[endIndex].push_back(end);
}
void addNext(ll d, ll x, ll index, vector<ll> & dp)
{
ll value = dp[index];
ll n = (ll)dp.size();
for(ll i = index + d; (i < n) && (i <= (index + d * x)); i+= d) {
dp[i] += value;
dp[i] %= mod;
}
}
void deletePrev(unordered_map<ll, unordered_map<ll, ll> > & pending,
unordered_map<ll, vector<vector<ll> > > & ending, ll index)
{
if(ending.find(index) != ending.end()){
auto & entries = ending[index];
for(auto & entry : entries){
ll d = entry[0], i = entry[1], count = entry[2];
pending[d][i] += mod - count;
pending[d][i] %= mod;
if(pending[d][i] == 0) {
pending[d].erase(i);
}
}
ending.erase(index);
}
}
void solve(ll n, vector<ll> &D, vector<ll> &X)
{
unordered_map<ll, unordered_map<ll, ll> > pending;
unordered_map<ll, vector<vector<ll> > > ending;
vector<ll> dp(n, 0);
dp[0] = 1;
for(int i = 0; i < n; i++) {
dp[i] += processPrev(pending, i);
dp[i] %= mod;
if(D[i] < (ll)sqrt(n)){
addNext(D[i], X[i], i, dp[i], n, pending, ending);
} else {
addNext(D[i], X[i], i, dp);
}
deletePrev(pending, ending, i);
}
cout << calculateTotal(dp);
}
int main() {
ll n=1;
cin>>n;
vector<ll> D;
vector<ll> X;
ll i = n;
while(i--)
{
ll d, x;
cin >> d >> x;
D.push_back(d);
X.push_back(x);
}
solve(n, D, X);
return 0;
}
