#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;
using namespace std;
using ll = long long;
using ld = long double;
struct custom_hash {
static uint64_t splitmix64(uint64_t x) {
// http://xorshift.di.unimi.it/splitmix64.c
x += 0x9e3779b97f4a7c15;
x = (x ^ (x >> 30)) * 0xbf58476d1ce4e5b9;
x = (x ^ (x >> 27)) * 0x94d049bb133111eb;
return x ^ (x >> 31);
}
size_t operator()(uint64_t x) const {
static const uint64_t FIXED_RANDOM = chrono::steady_clock::now().time_since_epoch().count();
return splitmix64(x + FIXED_RANDOM);
}
};
gp_hash_table<ll, ll, custom_hash> app;
//constexpr ll MOD = 998244353;
constexpr ll MOD = 1e9 + 7;
constexpr ll INF = 3e18;
ll n, m, k, q, x, y, z, w, h, T;
string s, t;
double p;
int main() {
ios_base::sync_with_stdio(0);
cin.tie(NULL);
cout.tie(NULL);
ll n;
cin >> n;
pair<ll, ll> a[n];
set<ll> s;
for (ll i = 0; i < n; i++) {
cin >> a[i].first >> a[i].second;
s.insert(a[i].first); s.insert(a[i].second);
}
map<ll, ll> app;
ll diff[2 * n + 10] = {};
ll pr = 0;
ll cur = 1;
for (ll val : s) {
app[val] = cur;
diff[cur] = val - pr;
pr = val;
cur++;
}
for (ll i = 0; i < n; i++) {
a[i].first = app[a[i].first]; a[i].second = app[a[i].second];
}
ll pref[cur] = {};
fill(pref, pref + cur, 1);
for (ll i = 0; i < n; i++) {
ll dp[cur] = {};
dp[a[i].first] = pref[a[i].first - 1];
for (ll j = a[i].first + 1; j <= a[i].second; j++) {
dp[j] = (pref[j - 1] * diff[j]) % MOD;
}
ll ad = 0;
for (ll j = 1; j < cur; j++) {
ad += dp[j];
if (ad >= MOD) ad -= MOD;
pref[j] += ad;
if (pref[j] >= MOD) pref[j] -= MOD;
}
}
ll ans = (pref[cur - 1] - 1 + MOD) % MOD;
printf("%lld\n", ans);
}
