Pagini recente » Cod sursa (job #1505622) | Cod sursa (job #2232431) | Cod sursa (job #2806357) | Cod sursa (job #2039198) | Cod sursa (job #1065324)
#include <algorithm>
#include <fstream>
#include <bitset>
using namespace std;
const int N=1000005;
ifstream fin("mins.in");
ofstream fout("mins.out");
int d[N];
bitset <N> v;
int main()
{
int n, m, mins;
long long i, j, sol;
fin>>n>>m;
n--; m--;
sol=1LL*n*m;
mins=min(n, m);
for(i=2;i<=mins;i++)
{
if(!v[i])
{
if(!d[i])
{
for(j=i+i;j<=mins;j+=i) d[j]++;
for(j=i*i;j<=mins;j+=i*i) v[j]=1;
}
if(d[i]%2) sol+=(n/i)*(m/i);
else sol-=(n/i)*(m/i);
}
}
fout<<sol;
}