/*
Mayoeba Yabureru
*/
#include<bits/stdc++.h>
using namespace std;
void solve() {
int n, sq = sqrt(1e5);
long long mod = 1e9 + 7, ans = 0;
cin >> n;
vector<int> d(n + 1), x(n + 1);
vector<long long> dp(n + 1);
vector<vector<int>> remove(n + 1);
vector sumdp(sq + 1, vector<long long>(sq + 1));
dp[1] = 1;
for (int i = 1; i <= n; i ++) cin >> d[i] >> x[i];
for (int i = 1; i <= n; i ++) {
for (int j = 1; j <= sq; j ++) dp[i] = (dp[i] + sumdp[j][i % j]) % mod;
ans = (ans + dp[i]) % mod;
if (d[i] > sq) {
for (int j = i + d[i]; j <= n; j += d[i]) {
x[i] --;
dp[j] = (dp[j] + dp[i]) % mod;
if (x[i] == 0) break;
}
}
else if (d[i]) {
sumdp[d[i]][i % d[i]] = (sumdp[d[i]][i % d[i]] + dp[i]) % mod;
long long next = i + x[i] * d[i];
if (next <= n) remove[next].push_back(i);
}
for (auto j : remove[i]) sumdp[d[j]][j % d[j]] = (sumdp[d[j]][j % d[j]] - dp[j] + mod) % mod;
}
cout << ans;
}
/*
5
1 3
2 1
1 3
0 10
3 5
*/
int main()
{
int T = 1;
for (int I = 0; I < T; I ++){
solve();
}
}
