#include <fstream>

using namespace std;

int main(void)
{
    int n, m, k, v1[100000], v2[100000];
    ifstream f("stergeri.in");
    ofstream g("stergeri.out");

    f >> n >> m >> k;

    for (int i = 0; i < m; i++)
        f >> v1[i] << v2[i];

    for (int i = m - 1; i >= 0; i--)
        if (v1[i] >= k)
            k += v2[i] - v1[i] + 1;

    g << k;

    f.close();
    g.close();

    return 0;
}