PROGRAMMING:Rational addition
This problem requires the preparation of procedures to calculate the sum of two rational numbers.
###Input format:
Input two rational numbers in the form of fraction in one line according to the format of 'A1 / B1 A2 / B2', where the numerator and denominator are all positive integers in the range of shaping.
###Output format:
In a row, output the sum of two rational numbers in the format of 'A / B'. Note that it must be the simplest fractional form of the rational number. If the denominator is 1, only the numerator will be output.
###Input sample 1:
```in
1/3 1/6
```
###Output sample 1:
```out
1/2
```
###Input example 2:
```
4/3 2/3
```
###Output example 2:
```
two
```
answer：If there is no answer, please comment
###Input format:
Input two rational numbers in the form of fraction in one line according to the format of 'A1 / B1 A2 / B2', where the numerator and denominator are all positive integers in the range of shaping.
###Output format:
In a row, output the sum of two rational numbers in the format of 'A / B'. Note that it must be the simplest fractional form of the rational number. If the denominator is 1, only the numerator will be output.
###Input sample 1:
```in
1/3 1/6
```
###Output sample 1:
```out
1/2
```
###Input example 2:
```
4/3 2/3
```
###Output example 2:
```
two
```
answer：If there is no answer, please comment