// 23 - 12 - 23
#include<bits/stdc++.h>
using namespace std;
#define read() ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0)
#define day() time_t now = time(0);char* x = ctime(&now);cerr<<"Right Now Is : "<<x<<"\n"
#define int long long
#define ii pair<int,int>
#define X first
#define Y second
const long long MAX = (int)1e5 + 5;
const long long INF = (int)1e9;
const long long MOD = (int)1e9 + 7;
const int Block = 10;
int n,d[MAX],x[MAX];
int dp[MAX],f[MAX][Block + 5];
signed main(){
read();
cin >> n;
for(int i = 1;i <= n;i++)cin >> d[i] >> x[i];
for(int i = n;i >= 1;i--){
//cout << d[i] << " " << x[i] << " " << d[i] << "\n";
dp[i] = 0;
if(d[i] == 0){
dp[i] = 1;
}else if(d[i] > Block){
for(int j = i + d[i];j <= min(n,i + d[i] * x[i]);j += d[i]){
dp[i] = (dp[i] + dp[j]) % MOD;
}
dp[i] = (dp[i] + 1) % MOD;
}else{
//cout << i << " " << d[i] << "\n";
dp[i] = 1;
dp[i] = (dp[i] + ((i + d[i] <= n) ? (f[i + d[i]][d[i]]) : (0))) % MOD;
//int cost1 = ((i + d[i] <= n) ? (f[i + d[i]][d[i]]) : (0));
dp[i] = (dp[i] - ((i + d[i] * (x[i] + 1) <= n) ? (f[(i + d[i] * (x[i] + 1))][d[i]]) : 0) + MOD * MOD) % MOD;
//int cost2 = ((i + d[i] * (x[i] + 1) <= n) ? (f[(i + d[i] * (x[i] + 1))][d[i]]) : 0);
//cout << i << " " << cost1 << " " << cost2 << " " << d[i] << "\n";
}
//cout << dp[i] << "\n";
for(int j = 0;j <= Block;j++){
f[i][j] = ((i + j <= n ? f[i + j][j] : 0) + dp[i]) % MOD;
//cout << f[i][j] << " \n"[j == Block];
}
}
//for(int i = 1;i <= n;i++)cout << dp[i] << " \n"[i == n];
cout << dp[1];
}
