#include <bits/stdc++.h>
#define int long long
using namespace std;
const int MAXN = 1e5+5;
const int MOD = 1e9+7;
int dp[MAXN],ad[MAXN][317];
signed main()
{
ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
int N; cin >> N;
int B = sqrt(N);
dp[1] = 1; int ans = 0;
for(int i = 1;i<=N;++i){
int d,x; cin >> d >> x;
for(int j = 1;j<=B;++j){
if(i+j <= N) ad[i+j][j] = (ad[i+j][j]+ad[i][j])%MOD;
dp[i] = (dp[i]+ad[i][j])%MOD;
}
ans = (ans+dp[i])%MOD;
if(d == 0) continue;
if(d > B){
int maxx = min(N,i+x*d);
for(int j = i+d;j<=maxx;j += d){
dp[j] = (dp[j]+dp[i])%MOD;
}
}
else{
ad[i+d][d] = (ad[i+d][d]+dp[i])%MOD;
if(i+d*(x+1) <= N) ad[i+d*(x+1)][d] = (ad[i+d*(x+1)][d]-dp[i]+MOD)%MOD;
}
}
cout << ans << "\n";
return 0;
}
