/*
the author :
Luffy-san
"yazan sharba"
*/
#include <bits/stdc++.h>
using namespace std;
/*
⠀⠀⠀⠀⠀⠀⠀⠙⢦⡀⠀⠀⠀⠀⠀⠀⠀⠀⠀⢀⡠⠒⠁⠀⠀⠀⠀⠀⠘⢿⣆⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠘⢷⣄⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀
⠀⠀⠀⠀⠀⠀⠀⠀⠀⠉⠓⠤⠤⠤⠤⠄⠒⠒⠉⠁⠀⠀⠀⠀⠀⠀⠀⠀⠀⠈⢻⣦⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠈⣻⣷⣄⡀⠀⠀⠀⠀⠀⠀⠀⠀
⠶⣦⡀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠙⢷⣦⣀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⣠⡴⠟⠉⠀⠙⢿⣷⣦⣤⣀⣀⣀⡀⠄
⠀⠀⠙⢦⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠈⠛⠿⢶⣤⣄⣀⡀⠀⠀⠀⣀⣀⣤⣤⡶⠟⠋⠀⠀⠀⠀⠀⠘⢿⣿⣿⠁⠀⠀⠀⠀
⠀⠀⠀⠀⢲⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⣀⣤⣾⠃⠀⠀⠀⠀⠀⠀⠀⠀⠈⠛⠻⣿⣶⣶⣿⡿⠿⠛⠁⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠙⣿⡇⠀⠀⠀⠀
⠳⡄⠀⠀⣸⡄⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⢀⣠⣤⣤⣷⣾⣿⠟⠁⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⣀⣴⡿⠋⠉⠉⠁⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⢹⡇⠀⠀⠀⠀
⠀⢹⡀⢠⡟⠀⠀⠀⠀⠀⢀⣴⠀⠀⠀⠀⠀⢀⣴⡿⠋⠉⠹⣿⡿⠁⠀⠀⠀⠀⠀⠀⠀⠀⢀⣠⣴⣾⡿⠋⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠈⣷⠀⠀⠀⠀
⠀⢠⣿⡟⠀⠀⠀⠀⠰⣴⡿⠃⠀⠀⠀⠀⢠⣾⣿⣧⡀⠀⠀⣿⠁⠀⠀⠀⠀⠀⠀⢀⣠⣶⡟⣫⡽⠉⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⢾⣧⠀⠀⠀
⣶⣿⡟⠀⠀⠀⠀⠀⣼⣿⠃⠀⠀⠀⠀⢠⣿⣿⢃⣿⣷⣄⢸⡟⠀⠀⠀⠀⠀⠀⣰⣿⣿⠿⠿⠿⣦⡀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⣦⣿⡆⠀⠀
⠻⣿⠀⠀⠀⠀⠀⣼⣿⣿⠀⠀⠀⠀⣠⣾⣿⠿⠋⠁⠈⣻⣾⣧⠀⠀⠀⠀⢀⣾⣿⡟⠁⣀⠀⠀⠀⠹⣧⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⢀⣤⠿⠛⣿⡀⠀
⣶⣿⣦⣀⣀⣤⣾⣿⡟⢿⣇⡀⠀⢀⣿⣿⠋⠀⣠⣾⠟⣿⣿⣿⡀⠀⠀⠀⣸⡟⢻⡆⠈⢻⣿⠀⠀⢠⡿⠀⢰⡇⠀⠀⠀⠀⢀⣤⠶⢶⣄⠀⠀⠀⠀⠀⣠⡴⠟⠁⠀⠀⣿⡇⠀
⣿⠁⠉⠻⣿⣿⣿⡏⠁⠘⢿⣷⣶⣿⡿⠃⠀⠀⣿⣁⣶⣿⣿⣿⣇⡀⠀⣀⣿⣅⠈⠛⠷⠛⠁⠀⢀⣾⠇⢠⡾⠀⠀⠀⣠⡶⠋⠁⠀⠀⠹⣧⠀⢀⣴⠾⠋⠀⠀⢀⣤⣾⣿⡇⠀
⢿⡇⠀⠀⢻⣿⠇⠀⠀⠀⠈⣿⠟⠻⣇⠀⠀⠀⢿⣏⠻⣿⠏⢉⣿⣿⠿⠿⠿⢿⣦⣀⠀⣀⣠⣴⡿⢋⣴⠟⠁⠀⠀⣴⠟⠀⢠⣤⠀⠀⣰⣿⠿⠋⠁⠀⢀⣠⣴⡿⠟⢉⣿⡇⠀
⠈⠿⣶⣤⣼⣿⠀⠀⠀⠀⠀⠀⠀⠀⢻⣆⠀⠀⠈⢿⣿⣿⣾⠿⠛⠁⠀⠀⠀⢸⣿⣿⢿⣟⠿⠛⠛⠛⠁⠀⠀⠀⣸⣿⠀⠀⠙⢷⣶⠟⠋⠀⠀⣀⣤⣾⣿⡟⠁⠀⢺⣾⡿⠀⠀
⠉⠀⠈⠉⠃⣿⠀⠀⠀⠀⠀⠀⠀⠀⠀⠙⢷⣄⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⢀⣾⠛⢻⣎⣿⠀⠀⠀⠀⠀⠀⢀⣴⣿⣿⣷⣤⣤⣤⣤⣴⣶⣾⣿⡋⠁⠀⢻⡇⠀⠀⣼⡟⠁⠀⠀
⣦⠀⠀⠀⠀⣿⡀⠀⠀⠀⠀⠀⣶⡀⠀⠀⠀⠙⠛⠶⣤⣄⣀⣀⣠⣤⡴⠾⠛⠁⠀⠈⠉⠙⠀⠀⠀⠀⠀⢠⣿⠟⠉⣿⠋⢹⣿⣏⣴⣿⣷⠞⣻⡟⠀⠀⢸⣷⣠⣼⠏⠀⠀⠀⠀
⢿⣿⣦⣤⣀⣿⡇⠀⠀⠀⢀⣴⠿⣷⣄⠀⠀⠀⠀⠀⠀⠈⠉⠁⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⣼⡟⠀⠀⣿⠀⠘⢿⣭⣛⣛⣛⣴⡿⠁⠀⠀⣸⣿⣿⠃⠀⠀⠀⠀⠀
⠀⠙⠻⣿⣿⣿⣧⠀⠀⠀⣸⡏⠀⠈⠻⣷⣄⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⢀⡀⣿⠁⠀⠀⠹⣧⡀⠀⠉⠙⠛⠉⠁⠀⠀⣠⡾⠛⠛⣿⠀⠀⠀⠀⣠⡟
⠀⠀⠀⠀⠙⠿⣿⣷⡀⠀⣿⠁⠀⠀⠀⠈⢿⣷⣤⡀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⡟⠀⣿⠀⠀⠀⠀⠈⠛⠶⠶⢤⡶⠶⠶⠿⠛⠁⠀⠀⠀⣿⣷⡶⠞⡩⠛⠀
⠀⠀⠀⠀⠀⠀⠘⠻⢿⣄⣿⡀⠀⠀⠀⢰⠟⠈⠙⠿⣷⣤⣀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⣀⠀⠀⠀⣃⣰⣿⠀⠀⢀⣤⣀⠀⠀⠀⠀⡀⠀⣀⣶⠶⠛⠀⠀⣼⣿⣿⠿⠋⢀⣠⠆
⠀⠀⠀⠀⠀⠀⠀⠀⠀⠙⢿⣧⡀⠀⢀⡟⠀⠀⠀⠀⠈⠙⠻⢷⣦⣄⡀⠀⠀⠀⠀⠀⠀⠙⣷⣄⣴⣿⡿⠋⠀⠀⠀⠈⠙⠛⠛⠒⠲⣿⠛⠉⠁⠀⠀⢀⣾⠋⠉⠀⣀⣴⣿⡟⠃
⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠈⠙⣷⡄⣾⠁⠀⠀⠀⠀⠀⠀⢀⡾⠉⠙⠛⠿⣶⣦⣄⣀⠀⠀⠈⠛⠛⠡⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⣠⣿⠀⠀⠀⠀⣰⣿⣃⣤⣶⠾⠛⠉⠁⠀⠀
⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠈⢿⣿⡄⠀⠀⠀⠀⠀⠀⡾⠀⠀⠀⠀⠀⠀⠈⢹⡟⠻⠷⠶⣤⣤⣤⣤⣤⣤⣤⣤⣤⣤⣤⣤⣴⠟⠁⠀⠀⢀⣼⣿⣿⠟⠉⠀⠀⠀⠀⠀⠀⠀
⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠈⣿⠿⣶⣄⠀⠀⠀⡼⠁⠀⠀⠀⠀⠀⠀⢀⡾⠁⠀⠀⠀⠀⣸⠋⠉⠈⠉⠉⣿⠉⠀⣠⠞⠁⠀⠀⠀⣀⣿⡿⠋⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀
⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⣿⡇⠀⠙⠻⣦⣴⡃⠀⠀⠀⠀⠀⠀⢀⡾⠁⠀⠀⠀⠀⢰⡟⠀⠀⠀⠀⣸⢇⣠⠾⠉⠀⠀⠀⢀⣴⡿⠋⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀
⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⢹⣷⡄⠀⠀⠠⣍⡛⠶⣤⣄⡀⠀⠀⡾⠁⠀⠀⠀⠀⢠⡟⠀⠀⠀⣀⣴⡿⠛⠁⠀⠀⠀⢀⣴⣿⠟⠀⠀⠀⠀⠀⠀⠀⠀⠀⢀⠄⠒⠉⠁
⠱⡀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⣾⣿⣿⣦⣀⠀⠀⠉⠒⠤⢍⣛⠳⠾⠷⢤⣤⣤⣤⣤⣾⣤⡴⠶⠟⠋⠁⠀⠀⠀⠀⢀⣴⣿⡿⠋⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠁⠀⠀⠀⠀
⠀⢣⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⣿⣿⣿⣿⣿⣷⣶⣤⣤⣀⣤⣄⣀⠀⠐⠒⠒⠂⠤⠤⠤⠄⠐⠀⠀⠀⢀⣀⣠⣴⣾⡿⢋⡿⠃⠀⠀⠀⠀⠀⠀⠀⠀⠐⠁⠀⠀⠀⠀⠀⠀
⠀⠀⠇⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⣿⣯⠉⠛⠿⣿⣷⣍⠙⠻⣿⠿⠿⢿⣿⣷⣶⣿⣷⣶⣶⣶⣶⡶⣾⣿⣿⡿⢿⣿⣿⣶⣿⠃⠀⠀⠀⠀⠀⠀⠀⠀⠈⠀⠀⠀⠀⠀⠀⠀⠀
⠀⠀⠸⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⢿⣿⣷⠀⠀⠈⠉⠛⠿⣦⣅⠀⠀⠀⠈⠉⠉⠉⠉⣿⣿⣿⣿⡷⠿⠋⠁⢀⣾⣿⡟⣿⠃⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀
⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠘⣿⣿⡆⠀⠀⠀⠀⠀⠈⠙⢿⣦⡀⠀⠀⣀⣀⣤⣾⠿⠛⠁⠀⠀⠀⢠⣾⣷⠏⢸⣿⠃⠀⠀⠀⠀⠀⠀⠀⢰⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀
⠀⠀⡇⠠⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⢹⣯⢿⣄⠀⠀⠀⠀⠀⠀⠀⠉⠻⣦⣀⣉⣽⠟⠁⠀⠀⠀⠀⠀⢠⣿⣿⠏⠀⣾⣿⠀⠀⠀⠀⠀⠀⠀⠀⡇⠀⠀⠀⠀⠀⠀⠀⠀⠈⠀
⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⢹⣦⡙⢿⣶⣤⡄⠀⠀⠀⠀⠀⣀⡙⣓⡀⠀⠀⠀⠀⢀⣴⣴⣿⣿⠋⠀⠀⣿⡟⠀⠀⠀⠀⠀⠀⠀⠀⠃⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀
*/
#define yon(x) cout<<((x)?"YES\n":"NO\n");
#define all(x) x.begin(),x.end()
#define rall(x) x.rbegin(),x.rend()
#define ff first
#define ss second
#define em emplace
#define emp emplace_back
#define pb push_back
#define rep(i,j,k) for(int i=(j);bool(i<=(k));i++)
#define per(i,j,k) for(int i=(k);bool(i>=(j));i--)
#define forp(x,y,a) for(auto &[x,y]:(a))
#define mkp make_pair
typedef long long ll;
typedef pair<ll,ll> pll;
typedef vector<ll> vl;
typedef vector<pll> vpl;
typedef vector<vl> vvl;
typedef vector<vpl> vvpl;
typedef vector<string> vs;
typedef vector<set<ll> >vst;
typedef deque<ll> dl;
const ll inf =1e18+1;
const int N=1e6+1;
const ll dx[]={1,0,-1,0};
const ll dy[]={0,1,0,-1};
const ll mod1=998244353;
const ll mod=1e9+7;
const int LOG=21;
char dir[]={'D','R','U','L'};
void solve() {
ll n;
cin>>n;
vl dp(n,1);
vpl a(n);
rep(i,0,n-1)cin>>a[i].ff>>a[i].ss;
vvl s(100,vl(n));
per(i,0,n-1) {
if (a[i].ff>=100) {
rep(j,1,a[i].ss) {
if (i+j*a[i].ff>=n)break;
dp[i]+=dp[i+j*a[i].ff];
dp[i]%=mod;
}
}else {
if (a[i].ff>0) {
if (a[i].ff+i<n)
dp[i]+=s[a[i].ff][i+a[i].ff];
dp[i]%=mod;
if (i+1LL*a[i].ff*(1+a[i].ss)<n)dp[i]-=s[a[i].ff][i+1LL*a[i].ff*(1+a[i].ss)];
dp[i]+=mod;
dp[i]%=mod;
}
}
rep(j,1,99) {
if (i+j<n) {
s[j][i]=s[j][i+j];
s[j][i]%=mod;
}else {
s[j][i]=0;
}
s[j][i]+=dp[i];
s[j][i]%=mod;
// cout<<s[j][i]<<" ";
}
cout<<"\n";
}
cout<<dp[0];
}
signed main(){
ios_base::sync_with_stdio(NULL);
cin.tie(nullptr);
cout.tie(nullptr);
#ifdef Usaco
string f="disrupt";
freopen((f+".in").c_str(),"r",stdin);
freopen((f+".out").c_str(),"w",stdout);
#endif
int t = 1;
//cin >> t;
while (t--) {
solve();
cout<<"\n";
}
}
/*
⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⢀⡀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀
⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⣴⣿⣿⠀⠀⠀⢠⣾⣧⣤⡖⠀⠀⠀⠀⠀⠀⠀
⠀⠀⠀⠀⠀⠀⠀⠀⢀⣼⠋⠀⠉⠀⢄⣸⣿⣿⣿⣿⣿⣥⡤⢶⣿⣦⣀⡀
⠀⠀⠀⠀⠀⠀⠀⠀⣿⣿⡆⠀⠀⠀⣙⣛⣿⣿⣿⣿⡏⠀⠀⣀⣿⣿⣿⡟
⠀⠀⠀⠀⠀⠀⠀⠀⠙⠻⠷⣦⣤⣤⣬⣽⣿⣿⣿⣿⣿⣿⣿⣟⠛⠿⠋⠀
⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⢀⣴⠋⣿⣿⣿⣿⣿⣿⣿⣿⢿⣿⣿⡆⠀⠀
⠀⠀⠀⠀⣠⣶⣶⣶⣿⣦⡀⠘⣿⣿⣿⣿⣿⣿⣿⣿⠿⠋⠈⢹⡏⠁⠀⠀
⠀⠀⠀⢀⣿⡏⠉⠿⢿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣷⡆⠀⢀⣿⡇⠀⠀⠀
⠀⠀⠀⢸⣿⠀⠀⠀⠀⠀⠙⢿⣿⣿⣿⣿⣿⣿⣿⣿⣟⡘⣿⣿⣃⠀⠀⠀
⣴⣷⣀⣸⣿⠀⠀⠀⠀⠀⠀⠘⣿⣿⣿⣿⠹⣿⣯⣤⣾⠏⠉⠉⠉⠙⠢⠀
⠈⠙⢿⣿⡟⠀⠀⠀⠀⠀⠀⠀⢸⣿⣿⣿⣄⠛⠉⢩⣷⣴⡆⠀⠀⠀⠀⠀
⠀⠀⠀⠋⠀⠀⠀⠀⠀⠀⠀⠀⠈⣿⣿⣿⣿⣀⡠⠋⠈⢿⣇⠀⠀⠀⠀⠀
⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠙⠿⠿⠛⠁⠀⠀⠀⠀⠀⠀⠀⠀⠀
⠀⠀⠀⠀⠀
*/
