nrreg

#include <fstream>
#include <cmath>
using namespace std;
long double r[10001];

int main()
{
    int n;
    ifstream f("nrreg.in");
    f>>n;
    f.close();
    r[0]=1;
    int c=0;
    for(int i=0,j=0,k=0;c<=n;)
    {
        long double Min=min(min(r[i]*2,r[j]*3),r[k]*5);
        if(Min==r[i]*2)
            ++i;
        else
            if(Min==r[j]*3)
                ++j;
            else
                if(Min==r[k]*5)
                    ++k;
        if(Min!=r[c])
            r[++c]=Min;
    }
    ofstream g("nrreg.out");
    for(long double i=r[n-1];r[n-1]>=1;--i)
        if(sqrt(r[n-1]/i)*sqrt(r[n-1]/i)==r[n-1]/i)
        {
            g<<(unsigned long long int)r[n-1]<<' '<<(unsigned long long int)r[n-1]/i<<' '<<(unsigned long long int)i;
            g.close();
            break;
        }
    return 0;
}