#include <iostream>
#include <fstream>

using namespace std;

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

const int maxm = 1e5;
int x[maxm], y[maxm];

int main() {
    int n, m, k;
    fin >> n >> m >> k;
    for (int i = 0; i < m; i++)
        fin >> x[i] >> y[i];
    for (int i = m - 1; i > -1; i--)
        if (x[i] <= k)
            k += y[i] - x[i] + 1;
    fout << k << '\n';


    return 0;
}