#include <bits/stdc++.h>
#define int long long
using namespace std;
int n,x,y,k,m;
vector<pair<int, int>> v;

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

signed main()
{
    fin >> n >> m >> k;
    for(int i = 1; i <= m; i++){
        fin >> x >> y;
        v.push_back({x, y});
    }
    reverse(v.begin(), v.end());
    for(auto [st, dr]: v){
        if(st <= k){
            k += (dr-st)+1;
        }
    }
    fout << k;
    return 0;
}