#include <bits/stdc++.h>
using namespace std;
#define fast ios::sync_with_stdio(0);cin.tie(0);
typedef long long ll;
#define f first
#define s second
#define LOGN 61
const ll MOD = 1e9 + 7;
const ll MAXN = 1e5 + 100;
#define int long long
const ll SQ = 400;
vector<int> omit[MAXN];
int classes[400][400], dp[MAXN], d[MAXN], x[MAXN];
signed main() {
fast
int N;
cin >> N;
dp[1] = 1;
for (int i = 1; i <= N; i++) {
for (auto u : omit[i])
classes[d[u]][u % d[u]] = (classes[d[u]][u % d[u]] - dp[u] + MOD) % MOD;
for (int m = 1; m < 400; m++)
dp[i] = (dp[i] + classes[m][i % m]) % MOD;
cin >> d[i] >> x[i];
if (d[i] >= SQ) {
for (int j = i + d[i]; j <= min(N, i + d[i] * x[i]); j += d[i])
dp[j] = (dp[j] + dp[i]) % MOD;
} else if (d[i] != 0) {
classes[d[i]][i % d[i]] = (classes[d[i]][i % d[i]] + dp[i]) % MOD;
omit[min(N+1, i + d[i] * x[i] + 1)].push_back(i);
}
}
ll ans = 0;
for (int i = 1; i <= N; i++)
ans = (ans + dp[i]) % MOD;
cout << ans << "\n";
}
