#include <bits/stdc++.h>
using namespace std;
#define int long long
#define speedIO ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define mod 1000000007
#define f first
#define s second
#define pii pair<int,int>
#define pb push_back
vector<vector<vector<int>>> bit;//step,start,value
const int block=100;
void update(int idx, int val, int step, int start){
while(idx<=bit[step][start].size()){
bit[step][start][idx]=(bit[step][start][idx]+val)%mod;
idx+=idx&(-idx);
}
}
int get(int idx, int step, int start){
int ans=0;
while(idx>0){
ans=(ans+bit[step][start][idx])%mod;
idx-=(idx)&(-idx);
}
return ans;
}
int32_t main(){
speedIO;
int t,n,m,k,q;
//cin>>t;
t=1;
while(t--){
cin>>n;
vector<int> d(n+1),x(n+1),dp(n+1,0);
bit.resize(block,vector<vector<int>>(block));
for(int i=1;i<block;i++){
for(int j=0;j<block;j++){
bit[i][j].resize(n/i+5,0);
}
}
for(int i=1;i<=n;i++){
cin>>d[i]>>x[i];
}
dp[1]=1;
//update(1,1,1);
for(int i=1;i<=n;i++){
for(int j=1;j<=block-1;j++){
int start=i%j;
if(start==0){
start=j;
}
int tmp=i-start;
tmp/=j;
tmp+=1;
//if(j<6) cout<<"hi "<<i<<' '<<tmp<<' '<<j<<' '<<start<<'\n';
//if(j<6) cout<<"what "<<get(tmp,j,start)<<'\n';
dp[i]=(dp[i]+get(tmp,j,start))%mod;
}
if(d[i]==0) continue;
if(d[i]>=block){
for(int j=i+d[i];j<=min(i+x[i]*d[i],n);j+=d[i]){
dp[j]=(dp[j]+dp[i])%mod;
}
}else{
int start=i%d[i];
if(start==0){
start=d[i];
}
int l=i+d[i];
int r=min(i+x[i]*d[i],n);
//cout<<l<<' '<<r<<'\n';
if(l>r) continue;
int tmp=l-start;
tmp/=d[i];
tmp+=1;
//cout<<tmp<<' '<<dp[i]<<' '<<d[i]<<' '<<start<<'\n';
update(tmp,dp[i],d[i],start);
if(r==n){
//update(n,-dp[i],d[i],start);
}else{
tmp=r-start;
tmp/=d[i];
tmp+=2;
//cout<<tmp<<' '<<-dp[i]<<' '<<d[i]<<' '<<start<<'\n';
update(tmp,-dp[i],d[i],start);
}
}
}
/*cout<<'\n';
for(int i=0;i<=n+3;i++){
cout<<bit[1][1][i]<<' ';
}
cout<<'\n';
cout<<get(5,1,1)<<'\n';*/
int final=0;
for(int i=1;i<=n;i++){
final=(final+dp[i])%mod;
//cout<<dp[i]<<' ';
}
cout<<final<<'\n';
}
return 0;
}
