#include <bits/stdc++.h>

using namespace std;
const int N = 1e5; int x[1 + N], y[1 + N];
int main() {
    ifstream cin ("stergeri.in"); ofstream cout ("stergeri.out");
    int n, m, k; cin >> n >> m >> k;
    for (int i = 1; i <= m; i++) cin >> x[i] >> y[i];
    for (int i = m; i > 0; i--) if (k >= x[i]) k += y[i] - x[i] + 1;
    cout << k << "\n";
    return 0;
}