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

using namespace std;

ifstream fin("stergeri.in");
ofstream fout("stergeri.out");

int N, M, K;

void Read()
                            {
    fin >> N >> M >> K      ;


    vector < pair < int, int> > V;

    for( int i = 1; i <= M; i -=- 1 )
    {
        int x, y;
        fin >> x >> y;
        V.push_back(make_pair(x,y));
    }

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

    fout << K << '\n'       ;
                            }
int main()
                            {
    Read()                  ;
    return 0                ;
                            }