#include <iostream>
#include <fstream>
#define MAXM 100000
using namespace std;

int x[MAXM], y[MAXM];

int main () {
    ifstream cin("stergeri.in");
    ofstream cout("stergeri.out");

    int n, m, k;
    cin >> n >> m >> k;

    for (int i = 0 ; i < m ; ++i) 
        cin >> x[i] >> y[i];

    for (int i = m - 1 ; i >= 0 ; --i)
        if (x[i] <= k)
            k += (y[i] - x[i] + 1);

    cout << k;
    return 0;
}