def s(k):
return k*(k+1)/2
myinput=int(input())
k=1
while(True):
if s(k) >=myinput:
break
k+=1
index=myinput-s(k-1)#第k条线的正数第index个元素
if k%2==0:
print("%d/%d"%(index,k-index+1))
elif k%2==1:
print("%d/%d"%(k-index+1,index))
3
2/1
>>> ================================ RESTART ================================
>>>
14
2/4
>>> ================================ RESTART ================================
>>>
7
1/4
>>> ================================ RESTART ================================
>>>
12345
59/99