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

long sol, n, i, a, b, c, v[810];

int main() {
	freopen("nrtri.in", "r", stdin);
	freopen("nrtri.out", "w", stdout);
	scanf("%ld", &n);
	for (i = 1; i <= n; ++i) {
		scanf("%ld", &v[i]);
	}
	for (a = 1; a <= n; ++a) {
		for (b = a + 1; b <= n; ++b) {
			for (c = b + 1; c <= n; ++c) {
				if (a != b && b != c) {
					if (v[a] + v[b] >= v[c] && v[a] + v[c] >= v[b] && v[b] + v[c] >= v[a]) {
						++sol;
					}
				}
			}
		}
	}
	printf("%ld", sol);
	return 0;
}