#include<stdio.h> int main(){ __int64 n, i, odd, even; while(scanf("%I64d",&n)!=EOF){ odd=6; even=6; for(i=4;i<=n;i++){ if(i%2) odd=2*odd+even; else even=2*even+odd; } if(n==1) printf("3/n"); else if(n%2) printf("%I64d/n",odd); else printf("%I64d/n",even); } return 0; }