#include <bits/stdc++.h>
using namespace std;
#ifdef LOCAL
#include "debug.h"
#else
#define debug(...) 42
#endif
#define int long long
#define all(x) x.begin(), x.end()
const int mod = 1000000007;
const int S = 330;
const int N = 1e5 + 5;
int n, d[N], x[N], dp[N], de[N], ans = 0;
vector<int> rm[N];
int lz[N][S];
int32_t main() {
ios::sync_with_stdio(0);
cin.tie(0);
cin >> n;
for (int i = 1; i <= n; i++) {
cin >> d[i] >> x[i];
if (d[i] == 0 || d[i] > n) continue;
int dest = i;
for (int j = i; j <= min(n, i + x[i] * d[i]); j += d[i]) dest = j;
rm[dest].push_back(i);
de[i] = dest;
}
dp[1] = 1;
for (int i = 1; i <= n; i++) {
for (int j = 0; j < S; j++) dp[i] = (dp[i] + lz[i][j]) % mod;
for (int train : rm[i]) if (d[train] < S) lz[i][d[train]] = (lz[i][d[train]] - dp[train] + mod) % mod;
if (d[i] >= S) {
for (int j = i + d[i]; j <= de[i]; j += d[i]) dp[j] = (dp[j] + dp[i]) % mod;
} else {
lz[i][d[i]] = (lz[i][d[i]] + dp[i]) % mod;
for (int j = 0; j < S; j++) if (i + j <= n) lz[i + j][j] = (lz[i + j][j] + lz[i][j]) % mod;
}
ans = (ans + dp[i]) % mod;
}
cout << ans << '\n';
}
