#include <bits/stdc++.h>

using namespace std;

vector<pair<int, int>> V;

int main()
{
    long long N, M, K;
    ifstream f("stergeri.in");
    ofstream g("stergeri.out");

    f>>N>>M>>K;
    V.resize(M);
    for (int i = 0; i < M; ++i)
        f>>V[i].first>>V[i].second;

    for (int i = M-1; i >= 0; i--) {
        if (V[i].first <= K)
            K += V[i].second - V[i].first + 1;
    }

    g<<K;
    f.close();
    g.close();
}