Cod sursa(job #379176)

Utilizator ProtomanAndrei Purice Protoman Data 30 decembrie 2009 21:44:43
Problema Mins Scor 0
Compilator cpp Status done
Runda Arhiva de probleme Marime 0.57 kb
#include <algorithm>
#include <stdio.h>

#define MAX 10010
#define ll long long

using namespace std;

int phi[MAX];
int n, m;
ll sol;

int main()
{
	freopen("mins.in", "r", stdin);
	freopen("mins.out", "w", stdout);
	
	scanf("%d %d", &n, &m);
	n--, m--;
	if (n > m)
		swap(n, m);

	for (int i = 1; i <= m; i++)
		phi[i] = min(i, n);

	for (int i = 2; i <= n; i++)
		for (int j = 2 * i; j <= m; j += i)
			phi[j] -= phi[i];

	for (int i = 1; i <= m; i++)
		sol += phi[i];

	printf("%lld\n", sol);

	fclose(stdin);
	fclose(stdout);
	return 0;
}