#include <fstream>
#include <iostream>
using namespace std;

ifstream fin("stergeri.in");
ofstream fout("stergeri.out");

int n, m, k;
int a[100005];
int b[100005];

int main() {
    fin >> n >> m >> k;
    for (int i = 1; i <= m; i++) {
        fin >> a[i] >> b[i];
    }

    for (int i = m; i > 0; i--) {
        if (k >= a[i]) {
            k += (b[i] - a[i]) + 1;
        }
    }
    fout << k << '\n';
}