#include <iostream>
#include <vector>
#include <map>
#include <algorithm>
using namespace std;

vector<pair<int,int> > v;

int main() {
    freopen("stergeri.in", "r", stdin);
    freopen("stergeri.out", "w", stdout);
    int n, m, k, x, y;
    cin >> n >> m >> k;
    for (int i = 0; i < m; ++i) {
        cin >> x >> y;
        v.push_back(make_pair(x, y));
    }
    sort(v.begin(), v.end());
    for (auto it : v) {
        if (it.first <= k) {
            k += (it.second - it.first + 1);
        }
    }
    
    cout << k << "\n";
    return 0;
}