#include <stdio.h>
#include <math.h>

long n, m, k, i, j, p, sol, a[1000001], b[1000001]; 
char d[1000001];

int main() {
	freopen("stergeri.in", "r", stdin);
	freopen("stergeri.out", "w", stdout);
	scanf("%ld%ld%ld", &n, &m, &k);
	for (i = 1; i <= m; ++i) {
		scanf("%ld%ld", &a[i], &b[i]);
	}
	for (i = 1; i <= m; ++i) {
		p = 0;
		for (j = a[i]; p < b[i] - a[i] + 1; ++j) {
			if (d[j] != 1) {
				d[j] = 1;
				++p;
			}
		}
	}
	for (i = 1; i <= n; ++i) {
		if (d[i] == 0) {
			++sol;
			if (sol == k) {
				break;
			}
		}
	}
	printf("%ld\n", i);
	return 0;
}