/* Author : Mychecksdead */
#include<bits/stdc++.h>
using namespace std;
#define ll long long int
#define MOD (1000000000+7)
#define MOD1 (998244353)
#define pb push_back
#define all(x) x.begin(), x.end()
#define en cout << '\n'
#define ff first
#define ss second
#define pii pair<int,int>
#define vi vector<int>
const int N = 1e6+100, M = 1e5+10, K = 52, MX = 30, S = 300;
ll n, d[N], x[N];
ll dp[N], A[S][S];
vector<int> to[N], rem[N];
void solve(){
cin >> n;
for(int i = 1; i <= n; ++i){
cin >> d[i] >> x[i];
if(d[i] >= S){
int cur = i;
for(int j = 1; j <= x[i] && cur + d[i] <= n; ++j){
cur += d[i];
to[cur].pb(i);
}
}else{
if(d[i] != 0 && x[i] != 0)
rem[min(n+1, i+d[i]*x[i])].pb(i);
}
}
ll ans = 0;
for(int i = 1; i <= n; ++i){
dp[i] = (i == 1);
for(int j: to[i]){
dp[i] += dp[j];
if(dp[i] >= MOD) dp[i] -= MOD;
}
for(int j = 1; j < S; ++j){
dp[i] += A[j][i % j];
}
for(int j: rem[i]){
A[d[j]][j % d[j]] -= dp[j];
if(A[d[j]][j % d[j]] < 0) A[d[j]][j % d[j]] += MOD;
}
if(d[i] != 0 && d[i] < S && x[i] != 0){
A[d[i]][i % d[i]] += dp[i];
if(A[d[i]][i % d[i]] >= MOD) A[d[i]][i % d[i]] -= MOD;
}
ans += dp[i];
if(ans >= MOD) ans -= MOD;
}
cout << ans;
}
int main(){
cin.tie(0); ios::sync_with_stdio(0);
int tt = 1, aa;
// freopen("in.txt", "r", stdin);
// freopen("out.txt", "w", stdout);
while(tt--){
solve();
en;
}
cerr<<"time taken : "<<(float)clock()/CLOCKS_PER_SEC<<" seconds\n";
return 0;
}
