#include <bits/stdc++.h>
using namespace std;

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

const int NMAX=100002;
int st[NMAX],dr[NMAX],n,m,k;

int main()
{
    fin>>n>>m>>k;
    for(int i=1;i<=m;++i)
        fin>>st[i]>>dr[i];
        
    for(int i=m;i>0;--i)
        if(st[i]<=k)
            k=k+dr[i]-st[i]+1;
            
    fout<<k;
    return 0;
}