#include <bits/stdc++.h>

using namespace std;

ifstream fin("stergeri.in");
ofstream fout("stergeri.out");
vector<pair<int, int>> v;
int n, m, k, i, st, dr;

int main() {
    fin.tie(nullptr);
    fout.tie(nullptr);

    fin >> n >> m >> k;
    for(i = 1; i <= m; i++) {
        fin >> st >> dr;
        v.push_back({st, dr});
    }


    for(auto it = v.rbegin(); it != v.rend(); it++) {
        st = it->first;
        dr = it->second;

        if(st <= k) k += dr - st + 1;
    }
    fout << k;

    return 0;
}