// #pragma GCC optimize("O3,Ofast,unroll-loops")
#include <bits/stdc++.h>
using namespace std;
#define speedup cin.tie(0)->sync_with_stdio(0);
#define bitcount __builtin_popcount
#define all(x) begin(x), end(x)
#define int long long
#define pb push_back
#define vc vector
const int mod = 1e9 + 7, inf = 1e18;
inline bool chmax (int &a, int b) {if (a < b) {a = b; return 1;} return 0;}
inline void add (int &a, int b) {a = (a + b) % mod;}
inline void solve() {
int n; cin >> n;
vc<int> l (n + 1), r (n + 1), t;
for (int i = 1; i <= n; i++) {
cin >> l[i] >> r[i];
t.pb(l[i]);
t.pb(r[i]);
}
t.pb(inf);
sort(all(t));
t.erase(unique(all(t)), end(t));
for (int i = 1; i <= n; i++) {
l[i] = lower_bound(all(t), l[i]) - begin(t);
r[i] = upper_bound(all(t), r[i]) - begin(t);
}
int m = t.size();
vc<int> dp (m + 1);
for (int i = 1; i <= n; i++) {
int sum = 1;
for (int x = 0; x < r[i]; x++) {
int val = dp[x] * (t[x + 1] - t[x]);
if (x >= l[i]) add(dp[x], sum);
add(sum, val);
}
}
int ans = 0;
for (int x : dp) add(ans, x);
cout << ans;
}
signed main() {
speedup;
solve();
return 0;
}
