#include <bits/stdc++.h>
using namespace std;
#define ff first
#define ss second
#define bl ' '
#define endl '\n'
#define all(v) (v).begin(), (v).end()
#define comp(v) (v).erase(unique(all(v)), (v).end())
#define lbd(v,x) lower_bound(all(v), (x))-(v).begin()
#define ubd(v,x) upper_bound(all(v), (x))-(v).begin()
typedef long long ll;
typedef pair<int, int> pi;
typedef pair<pi, int> pii;
typedef pair<int, pi> ipi;
typedef pair<pi, pi> pipi;
typedef pair<ll, ll> pll;
const int MAXN = 550;//100100*5;
const ll MOD = 1e9+7;
const ll INF = 2e18;
vector<ll> v;
pll arr[MAXN];
ll dp[MAXN][MAXN*2], sum[MAXN][MAXN*2]; // dp[i][j] : choose jth interval for ith school
ll comb[MAXN*2][MAXN], fac[MAXN], rfac[MAXN];
ll cnt[MAXN][MAXN*2];
ll e[MAXN];
ll pw(ll a, ll b) {
if(b==0) return 1;
ll x=pw(a*a%MOD, b>>1);
if(b&1) x=x*a%MOD;
return x;
}
int main() {
ios_base::sync_with_stdio(0); cin.tie(0);
int n; cin>>n;
for(int i=1; i<=n; i++) {
cin >> arr[i].ff>>arr[i].ss;
v.push_back(arr[i].ff); v.push_back(arr[i].ss+1);
}
ll res=0;
e[0]=1;
for(int i=1;i<=n;i++) {
e[i]=1;
for(int j=1;j<i;j++) {
if(arr[j].ff<arr[i].ff) e[i]+=e[j];
}
res+=(e[i]%=MOD);
}cout<<res%MOD;
}
