#include<bits/stdc++.h>
#define ll long long
#define ldb long double
#define fi first
#define se second
#define sza(a) (int)a.size()
#define pir pair<int,int>
#define pirll pair<ll,ll>
using namespace std;
const int maxn = 5e2 + 5;
const int modu = 1e9 + 7;
pir a[maxn];
void input(int n){
for (int i = 1 ; i <= n ; i++) cin >> a[i].fi >> a[i].se;
}
namespace sub1_2{
map <int,int> M;
const int N = 1e6 + 5;
struct fenwick_tree{
ll fenwick[N];
void update(int x,int n,ll val){
while (x <= n){
fenwick[x] = (fenwick[x] + val) % modu;
x = x | (x + 1);
}
}
ll calc(int x){
ll res = 0;
while (x > 0){
res = (res + fenwick[x]) % modu;
x = x & (x + 1);
x--;
}
return res;
}
} fw;
void compress(int n){
vector <int> V;
for (int i = 1 ; i <= n ; i++)
for (int j = a[i].fi ; j <= a[i].se ; j++)
V.push_back(j);
sort(V.begin(),V.end());
int cur = 0,lst = 0;
for (int x : V){
if (x != lst){
lst = x;
cur++;
}
M[x] = cur;
}
}
ll solve(int n){
compress(n);
int lim = 0;
for (int i = 1 ; i <= n ; i++) lim = max(lim,M[a[i].se]);
for (int i = a[1].fi ; i <= a[1].se ; i++)
fw.update(M[i],lim,1);
for (int i = 2 ; i <= n ; i++){
for (int v = a[i].se ; v >= a[i].fi ; v--){
ll val = fw.calc(M[v] - 1) + 1;
fw.update(M[v],lim,val);
}
}
return fw.calc(lim);
}
}
int main(){
ios_base::sync_with_stdio(false);
cin.tie(0);cout.tie(0);
int n;
cin >> n;
input(n);
cout << sub1_2::solve(n);
return 0;
}
