Sum of fractions

Find the sum of two proper fractions $a/b$ and $c/d$. Present the result as an irreducible fraction. If the result is an integer, then print only this integer.

Input

One line contains four positive integers $a,b,c,d$ — the numerators and denominators of the fractions. All numbers do not exceed $1000$.

Output

Print the numerator and denominator of the resulting fraction, or an integer if the result is a whole number.

Examples