#include <bits/stdc++.h>
using namespace std;
#define int long long
#define pb push_back
#define sz(a) (int)a.size()
#define all(a) begin(a),end(a)
using ll = long long;
using ar2 = array<int,2>;
const int mxN = (int)1e5+10;
const int MOD = (int)1e9+7;
const int B = (int)330;
int n, ans;
int x[mxN], d[mxN];
int dp[mxN], pref[mxN];
int seg[mxN*2+10];
int tot[B][B];
int32_t main(){
cin >> n; dp[0] = 1;
for(int i = 0; i < n; i++)
cin >> d[i] >> x[i];
set<ar2> rem;
for(int i = 0; i < n; i++){
for(int j = 1; j < B; j++)
dp[i]+=tot[i%j][j], dp[i]%=MOD;
if(d[i]>=B){
for(int j = 1; j<=x[i] and d[i]; j++){
if(i+j*d[i]>=n) break;
dp[i+j*d[i]]+=dp[i];
dp[i+j*d[i]]%=MOD;
}
}
else if(d[i]){
int nx = i+x[i]*d[i];
if(nx<=n) rem.insert({nx, i});
tot[i%d[i]][d[i]]+=dp[i];
tot[i%d[i]][d[i]]%=MOD;
}
while(sz(rem)){
auto [j,I] = *begin(rem);
if(j>i) break;
int l = I%d[I], l2 = d[I];
tot[l][l2]-=dp[I];
tot[l][l2]+=MOD;
tot[l][l2]%=MOD;
rem.erase(begin(rem));
}
ans+=dp[i]; ans%=MOD;
}
cout << ans << "\n";
}
