#include <iostream>
#include <fstream>
#define NMAX 100010

using namespace std;

ifstream f("stergeri.in");
ofstream g("stergeri.out");

int n,m,k,i,x[NMAX],y[NMAX];

int main()
{
    f>>n>>m>>k;
    for(i=1;i<=m;i++)
        f>>x[i]>>y[i];
    for(i=m;i>=1;i--)
        if (k>=x[i]) k+=(y[i]-x[i]+1);
    g<<k;
    return 0;
}