#include<bits/stdc++.h>
#define mp make_pair
#define PII pair<int,int>
#define fi first
#define se second
using namespace std;

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

const int NMAX=100005;

int n,m,k;
PII a[NMAX];

int main()
{
    int i;
    fin>>n>>m>>k;
    for (i=1;i<=m;i++) fin>>a[i].fi>>a[i].se;
    for (i=m;i>=1;i--)
        if (k>=a[i].fi)
            k+=a[i].se-a[i].fi+1;
    fout<<k<<"\n";
    return 0;
}