#include <bits/stdc++.h>
using namespace std;

#define endl '\n'

const int N = 1e6 + 6;

int main() {
	// ios::sync_with_stdio(0);
	// cin.tie(0); cout.tie(0);
	freopen("stergeri.in", "r", stdin);
	freopen("stergeri.out", "w", stdout);

	long long n, m, k;
	cin >> n >> m >> k;
	long long l[n], r[n];
	for(int i=0; i<m; i++) {
		cin >> l[i] >> r[i];
		r[i] = r[i] - l[i] + 1;
	}
	for(int i=m-1; i>=0; i--) {
		if(l[i] > k) continue;
		k += r[i];
	}
	cout << k << endl;

	return 0;
}