#include <bits/stdc++.h>
using namespace std;
int n,m,k;
ifstream fin("stergeri.in");
ofstream fout("stergeri.out");
int st[100005],dr[100005];
int main()
{
    int i,x,y;
    fin>>n>>m>>k;
    for(i=1;i<=m;i++)
        {
            fin>>x>>y;
            st[i]=x;
            dr[i]=y;
        }
     for(i=m;i>=1;i--)
            if(k>=st[i])k+=dr[i]-st[i]+1;
    fout<<k;
    fin.close();
    fout.close();

    return 0;
}