N=-int(input())+1
s=0
h=N>>1
c=[h,1][N&1]
for k in range(h+1,N+1):s,c=s*10+[-c,c][k&1],c*k*(N-k)//((k*2-N)*(k*2+1-N))
print(s,10**max(N,0),sep='/')