C++ :

#include <bits/stdc++.h>
#define M 1000005
using namespace std;
int d[M], n, a, b, r = 0, l = INT_MAX, ans[2], t = 1, ns;
int main() {
	scanf("%d", &n);
	for (int i = 0; i < n; ++i) {
		scanf("%d%d", &a, &b);
		l = min(l, a);
		r = max(r, b);
		++d[a], --d[b];
	}
	ns = l;
	bool q;
	for (int i = l; i <= r; ++i) {
		q = (d[i] += d[i - 1]) > 0;
		if (q != t || i == r) {
			ans[t] = max(ans[t], i - ns);
			ns = i;
			t = 1 - t;
		}
	}
	printf("%d %d\n", ans[1], ans[0]);
	return 0;
}