# start_oz





Given a string, return a string made of the first 2 chars (if present), however include first char only if it is 'o' and include the second only if it is 'z', so "ozymandias" yields "oz".

This exercise was taken from [codingbat.com](https://codingbat.com/prob/p199720) and has been adapted for the Python language. There are many great programming exercises there, but the majority are created for Java.






### Test 1
**Input:**
```
'ozymandias'
```
**Output:**
```
'oz'
```
### Test 2
**Input:**
```
'bzoo'
```
**Output:**
```
'z'
```
### Test 3
**Input:**
```
'oxx'
```
**Output:**
```
'o'
```
### Test 4
**Input:**
```
'oz'
```
**Output:**
```
'oz'
```
### Test 5
**Input:**
```
'ounce'
```
**Output:**
```
'o'
```
### Test 6
**Input:**
```
'o'
```
**Output:**
```
'o'
```
### Test 7
**Input:**
```
'abc'
```
**Output:**
```
''
```
### Test 8
**Input:**
```
''
```
**Output:**
```
''
```
### Test 9
**Input:**
```
'zoo'
```
**Output:**
```
''
```
### Test 10
**Input:**
```
'aztec'
```
**Output:**
```
'z'
```
### Test 11
**Input:**
```
'zzzz'
```
**Output:**
```
'z'
```
### Test 12
**Input:**
```
'oznic'
```
**Output:**
```
'oz'
```