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#include <iostream>
#include <vector>
#include <map>
#include <unordered_set>

using namespace std;

const long long MOD = 1e9 + 7;

int inv(int number) {
    if (number <= 1) { 
        return number; 
    }
    return MOD - MOD / number * inv(MOD % number) % MOD;
}

int main() {
    ios::sync_with_stdio(false);
    std::cin.tie(nullptr);

    int n;
    cin >> n;

    vector<pair<int, int>> shelfs;
    for (int i = 0; i < n; i++) {
        int a, b;
        cin >> a >> b;
        shelfs.push_back({a, b});
    }

    long long result = 0;
    map<int, unordered_set<int>> streams;
    for (int i = shelfs.size() - 1; i >= 0; i--) {
        auto beginIter = streams.lower_bound(shelfs[i].first);
        auto endIter = streams.upper_bound(shelfs[i].second);
        unordered_set<int> faucets;
        for (auto iter = beginIter; iter != endIter;) {
            for (int faucet : iter->second) {
                faucets.insert(faucet);
            }
            iter = streams.erase(iter);
        }
        faucets.insert(i);
        streams[shelfs[i].first] = faucets;
        streams[shelfs[i].second] = faucets;
        result = (result + inv(faucets.size())) % MOD;
    }

    cout << result << endl;

}