#include <bits/stdc++.h>
#define nmax 100002
using namespace std;

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

int main()
{
    int i;
    ifstream fin("stergeri.in");
    fin >> n >> m >> k;
    for (i = 1; i <= m; ++i)
        fin >> a[i] >> b[i];
    fin.close();

    for (i = m; i >= 1; --i)
         if(k >= a[i])
            k += (b[i] - a[i] + 1);

    ofstream fout("stergeri.out");
    fout << k << "\n";
    fout.close();

    return 0;
}