#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int,int> pii;
typedef tuple<int,int,int> trio;
typedef vector<int> vi;
const int MOD = 1e9+7;
const int MAXN = 1e5+5;
#define all(x) x.begin(), x.end()
#define sz(x) (int)x.size()
#define mk make_pair
#define pb push_back
#define fr first
#define sc second
ll d[MAXN], x[MAXN];
ll dp[MAXN], sum[305][305];
vector<trio> rem[MAXN];
int main() {
int N;
cin >> N;
for(int i = 1; i <= N; i++)
cin >> d[i] >> x[i];
ll tot = 0;
dp[1] = 1;
for(int i = 1; i <= N; i++) {
for(auto [a, b, c] : rem[i])
sum[a][b] = (sum[a][b] - c) % MOD;
for(int div = 1; div <= 300; div++)
dp[i] += sum[div][i%div];
dp[i] %= MOD;
tot = (tot + dp[i]) % MOD;
if(d[i] == 0) continue;
if(d[i] <= 300) {
int r = i%d[i];
sum[d[i]][r] = (sum[d[i]][r] + dp[i]) % MOD;
int max_pos = min(i + d[i] * x[i], (ll)N);
rem[max_pos+1].pb({d[i], r, dp[i]});
}
else {
for(int j = i+d[i], cnt = 1; j <= N and cnt < x[i]; j += d[i], cnt++)
dp[j] = (dp[j] + dp[i]) % MOD;
}
}
cout << tot << "\n";
}
