import sys
x = list(map(int, sys.stdin.readline().split()))
y = list(map(int, sys.stdin.readline().split()))

a = (x[0] * y[1] + x[1] * y[0]) 
b = (x[1] * y[1])
c = b - a

if c == 0:
    print(0)
elif c != 0:
    for i in range(1000, 1, -1):
        i = i - 1
        if c % i == 0 and b % i == 0:
            c = c // i
            b = b // i
    print(f'{c}/{b}')


5ed452ff035b6f2fa73fa95722f1c980225f6a61
<mask token>

<mask token>
if c == 0:
    print(0)
elif c != 0:
    for i in range(1000, 1, -1):
        i = i - 1
        if c % i == 0 and b % i == 0:
            c = c // i
            b = b // i
    print(f'{c}/{b}')

<mask token>
x = list(map(int, sys.stdin.readline().split()))
y = list(map(int, sys.stdin.readline().split()))
a = x[0] * y[1] + x[1] * y[0]
b = x[1] * y[1]
c = b - a
if c == 0:
    print(0)
elif c != 0:
    for i in range(1000, 1, -1):
        i = i - 1
        if c % i == 0 and b % i == 0:
            c = c // i
            b = b // i
    print(f'{c}/{b}')

import sys
x = list(map(int, sys.stdin.readline().split()))
y = list(map(int, sys.stdin.readline().split()))
a = x[0] * y[1] + x[1] * y[0]
b = x[1] * y[1]
c = b - a
if c == 0:
    print(0)
elif c != 0:
    for i in range(1000, 1, -1):
        i = i - 1
        if c % i == 0 and b % i == 0:
            c = c // i
            b = b // i
    print(f'{c}/{b}')

import sys
x = list(map(int, sys.stdin.readline().split()))
y = list(map(int, sys.stdin.readline().split()))

a = (x[0] * y[1] + x[1] * y[0]) 
b = (x[1] * y[1])
c = b - a

if c == 0:
    print(0)
elif c != 0:
    for i in range(1000, 1, -1):
        i = i - 1
        if c % i == 0 and b % i == 0:
            c = c // i
            b = b // i
    print(f'{c}/{b}')

