#include <bits/stdc++.h>
#define int long long
#define pb push_back
#define F first
#define S second
using namespace std;
const int N = 2e5 + 10;
const int mod = 1e9 + 7;
const int inf = 1e9;
const int K = 300;
int d[N],x[N],dp[N],s[K][K];
int add(int x,int y) {
x += y;
if(x >= mod) x -= mod;
return x;
}
int sub(int x,int y) {
x -= y;
if(x < 0) x += mod;
return x;
}
void sadd(int &x,int y) {
x += y;
if(x >= mod) x -= mod;
}
void ssub(int &x,int y) {
x -= y;
if(x < 0) x += mod;
}
signed main() {
ios_base::sync_with_stdio(false);
cin.tie(NULL);
int n;
cin >> n;
dp[1] = 1;
for(int i = 1; i <= n; i++) cin >> d[i] >> x[i];
vector<array<int,3>>qs[n + 2];
for(int i = 1; i <= n; i++) {
for(auto X : qs[i]) ssub(s[X[0]][X[1]],X[2]);
for(int o = 1; o < K; o++) sadd(dp[i],s[i % o][o]);
if(!d[i]) continue;
if(d[i] >= K) {
for(int j = 1; j <= x[i] && i + j * d[i] <= n; j++) {
sadd(dp[i + j * d[i]],dp[i]);
}
}else {
sadd(s[i % d[i]][d[i]],dp[i]);
qs[min(n + 1,i + d[i] * (x[i] + 1))].pb({i % d[i],d[i],dp[i]});
}
}
int res = 0;
for(int i = 1; i <= n; i++) sadd(res,dp[i]);
cout << res;
return 0;
}
