poj1286
#include<stdio.h>
#include<string.h>
#include<stdlib.h>
#include<math.h>
#include<algorithm>
using namespace std;
__int64 gcd(__int64 a,__int64 b)
{
if (!b)
return a;
return gcd(b, a % b);
}
__int64 Pow(__int64 a,__int64 b)
{
__int64 i;
__int64 res=1;
for(i=0;i<b;i++)
{
res*=a;
}
return res;
}
int main()
{
__int64 n;
while(scanf("%I64d",&n),n+1)
{
if(n==0)
{
printf("0\n");
continue;
}
__int64 counter=0;
__int64 i;
__int64 counter2=0;//置换数
for(i=1;i<=n;i++)
{
counter+=Pow(3,gcd(i,n));
counter2++;
}
if(n&1)
{
counter+=Pow(3,(n+1)/2)*n;
counter2+=n;
printf("%I64d\n",counter/counter2);
}
else
{
counter+=Pow(3,n/2)*(n/2);
counter2+=(n/2);
counter+=Pow(3,(n/2)+1)*(n/2);;
counter2+=(n/2);
printf("%I64d\n",counter/counter2);
}
}
return 0;
}