#include <fstream>

using namespace std;

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

int n,m,k,af,i,x[100002],y[100002];

int main()
{
    fin >> n >> m >> k;
    for (i=1;i<=m;i++)
    {
        fin >> x[i] >> y[i];
    }
    for (i=m;i>=1;i--)
    {
        if (x[i]<=k) k+=(y[i]-x[i]+1);
    }
    if (k<=n) fout << k;
    else fout << n;

    return 0;
}