#include<bits/stdc++.h>
#define ll long long
#define fi first
#define se second
#define ii pair<ll,ll>
#define iii pair<ii,ll>
#define pb push_back
using namespace std;
const ll N=1e5+9;
const ll mod=1e9+7;
const ll S=320;
ll f[S+2][N],dp[N],i,j,n,x[N],d[N];
int main()
{
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
cout.tie(nullptr);
cin>>n;
for(i=1;i<=n;i++) cin>>d[i]>>x[i];
memset(dp,0,sizeof(dp));
memset(f,0,sizeof(f));
for(i=n;i>0;i--)
{
if(d[i]>=S)
{
for(j=i+d[i];j<=n;j+=d[i])
if((j-i)/d[i]<=x[i])
dp[i]+=dp[j];
}
else {
dp[i]+=f[d[i]][i];
if(i+(x[i]+1)*d[i]<=n) dp[i]-=f[d[i]][i+(x[i]+1)*d[i]];
}
dp[i]=(dp[i]+mod+1)%mod;
for(j=1;j<=S;j++)
{
f[j][i]=(f[j][i]+dp[i])%mod;
if(i>j)
f[j][i-j]=(f[j][i-j]+f[j][i])%mod;
}
}
cout<<dp[1];
}
/*
5
1 3
2 1
1 3
0 10
3 5
*/
