#include <stdio.h>

int main()
{
	int N, H, W;
	scanf("%d %d %d", &N, &H, &W);
	printf("%lld\n", (long long)N / 2 * ((N + 1) / 2) * (H - 1 + W - 1)); 
	fflush(stdout);
	return 0;
}