#include <bits/stdc++.h>

using namespace std;

ifstream fin("stergeri.in");
ofstream fout("stergeri.out");
long long n,m,x,y,i,a,b,k,h,j;
int main()
{
    fin>>n>>m>>k;
    for(i=1;i<=m;i++)
    {
        fin>>a>>b;
        if(i==1)
        {
            x=a;
            y=b;
        }
        else
        {
            j=0;
            while(h<=b)
            {
                j++;
                if(j<x || j>y)
                    h++;
            }
            if(a<x)
                x=a;
            if(j>y)
                y=j;
        }
    }
    if(k>=x && k<=y)
        fout<<y+x-1;
    return 0;
}