#include<bits/stdc++.h>
using namespace std;
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
#define int long long
#define double long double
#define ordered_set tree<int, null_type,less_equal<int>, rb_tree_tag,tree_order_statistics_node_update>
#define S second
#define F first
#define fall(i,a,n) for(int i=a;i<=n;i++)
#define rfall(i,a,n) for(int i=a;i>=n;i--)
#define pb push_back
#define all(x) x.begin(),x.end()
#define lsb(x) (x & -x)
#define sz(x) (int)x.size()
const int MAXN=2e5+10;
const int MAXL=19;
const int inf=1e14;
const int MOD=1e9+7;
const int HASHBASE=146527;
const int HASHMOD=1e9+7;
const int SQRT=350;
typedef pair<int,int> pii;
typedef tuple<int,int,int> trio;
typedef tuple<int,int,int,int> squad;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
int n,v[MAXN],lim[MAXN],dp[MAXN],somadp[MAXN][SQRT];
int32_t main(){
std::ios_base::sync_with_stdio(false);
cin.tie(NULL);
cin>>n;
fall(i,1,n) cin>>v[i]>>lim[i];
rfall(i,n,1){
dp[i]=1;
if(v[i]>=SQRT){
for(int j=i+v[i];j<=min(n,i+v[i]*lim[i]);j+=v[i]) dp[i]=(dp[i]+dp[j])%MOD;
}
else if(v[i]){
int l=min(i+((n-i)/v[i])*v[i],i+v[i]*lim[i])+v[i];
dp[i]+=somadp[i+v[i]][v[i]];
dp[i]-=somadp[l][v[i]];
}
for(int j=1;j<SQRT;j++){
somadp[i][j]=dp[i]+somadp[i+j][j];
somadp[i][j]%=MOD;
}
}
dp[1]+=MOD;
cout<<dp[1]%MOD<<"\n";
}
