#include <fstream>
#include <vector>

using namespace std;

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

int main()
{
    int N, M, K;
    vector < pair<int,int> > V;

    fin >> N >> M >> K;

    for( int i = 1; i <= M; ++i )
    {
        int lf, rg;
        fin >> lf >> rg;

        V.push_back( { lf, rg } );
    }

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

    fout << K << '\n';

    return 0;
}