#include <bits/stdc++.h>
using namespace std;
using ll = long long;
const int MAXN = 3e5 + 10;
const int SQ = 540;
const ll MOD = 1e9 + 7;
int d[MAXN], x[MAXN];
ll dp[MAXN];
vector<ll> sum[SQ][SQ];
int n;
void update(int i){
for(int j=1; j<SQ; j++){
ll cur = (sum[j][i % j].back() + dp[i]) % MOD;
sum[j][i % j].push_back(cur);
}
}
ll get_sum(int d, int i, int x){
if(!d) return 0;
ll ans = 0;
if(d >= SQ){
int j = i + d;
while(j <= min((ll) n, i + (ll) d * x)){
ans = (ans + dp[j]) % MOD;
j += d;
}
return ans;
}
int sz = (int) sum[d][i % d].size();
ans = sum[d][i % d][sz - 1];
int pos = max(0, sz - x - 1);
ans = (ans - sum[d][i % d][pos] + MOD) % MOD;
return ans;
}
int main(){
cin.tie(0)->sync_with_stdio(0);
cin >> n;
for(int i=1; i<=n; i++) cin >> d[i] >> x[i];
for(int i=1; i<SQ; i++){
for(int j=0; j<i; j++){
sum[i][j].push_back(0);
}
}
dp[n] = 1;
update(n);
for(int i=(n - 1); i>=1; i--){
dp[i] = (1 + get_sum(d[i], i, x[i])) % MOD;
update(i);
// cout << "dp[" << i << "] = " << dp[i] << endl;
}
cout << dp[1] << "\n";
return 0;
}
