#include <iostream>
#include <fstream>
#include <vector>
#include <algorithm>

using namespace std;

const char iname[] = "stergeri.in";
const char oname[] = "stergeri.out";

vector <pair <int, int> > V;

int main(void)
{
    ifstream in(iname);
    ofstream out(oname);
    int N, M, K;
    int a, b;

    in >> N >> M >> K;
    for (int i = 0; i < M; ++ i) {
        in >> a >> b;
        V.push_back(make_pair(a, b));
    }
    for (int i = M - 1; i >= 0; -- i) {
        a = V[i].first, b = V[i].second;
        if (a <= K)
            K += b-a+1;
    }
    out << K;

    in.close(), out.close();
    return 0;
}