import math
A=int(input())
B=int(input())
C=int(input())
def lcm(a,b):
    return a*b//math.gcd(a,b)
def gcd(a,b):
    return math.gcd(a,b)
num1=B-A
den1=B*A
g1=gcd(num1,den1)
num1//=g1
den1//=g1
num2=C-B
den2=C*B
g2=gcd(num2,den2)
num2//=g2
den2//=g2
num3=lcm(den1,den2)
den3=gcd(num1,num2)
g3=gcd(num3,den3)
num3//=g3
den3//=g3
print('%d/%d' % (num3,den3))