#include <bits/stdc++.h>
using namespace std;
using ll = long long;
const int MAXN = 100'001;
const int K = 400;
const ll MOD = 1e9+7;
ll dp[MAXN];
ll cnt[MAXN][K];
ll d[MAXN], x[MAXN];
int main() {
ios::sync_with_stdio(0); cin.tie(0);
int n; cin >> n;
for (int i = 1; i <= n; i++) {
cin >> d[i] >> x[i];
}
for (int i = n; i >= 1; i--) {
if (d[i] >= K) {
dp[i] = 1;
for (ll j = i+d[i]; d[i] != 0 && j <= n && j <= i+d[i]*x[i]; j+=d[i]) {
dp[i] += dp[j];
dp[i] %= MOD;
}
dp[i] %= MOD;
} else {
dp[i] = 1;
if (d[i] != 0) {
if (i + d[i] <= n) dp[i] += cnt[i + d[i]][d[i]];
if (i + d[i] * (x[i] + 1) <= n) dp[i] -= cnt[i + d[i] * (x[i] + 1)][d[i]];
dp[i] %= MOD;
}
}
for (int j = 1; j < K; j++) {
cnt[i][j] = dp[i];
if (i + j <= n) cnt[i][j] += cnt[i+j][j];
cnt[i][j] %= MOD;
}
}
cout << (dp[1] + MOD) % MOD << "\n";
return 0;
}
