#include<fstream.h>

long n,m,k,x,y,min,max=1,j,i,SOL;

long minim(long a, long b)
    {
        if(a<b)
        return a;
        return b;
    }
int main()
{
    ifstream fin("stergeri.in");
    ofstream fout("stergeri.out");

    fin>>n>>m>>k;

    min=n;

    for(i=1;i<=m;++i)
        {
        fin>>x>>y;
        if(x<min||y<min)
            min=minim(x,y);
        max+=y-x+1;
        }

    for(i=1;i<=n;++i)
        {
        if(i<min||i>max)
            j++;
        if(j==k)
            {
            SOL=i;
            }
        }

    fout<<SOL;

    fin.close();
    fout.close();

}