#include <fstream>

#define NMAX 100005

using namespace std;

ifstream f("stergeri.in");
ofstream g("stergeri.out");

long long a[NMAX] , b[NMAX];
long long n , m , k;

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

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

    g << k;
    return 0;
}