## doppelganger
### Instructions
You are given 2 strings. Find out if first string contains second string. If it does, return index of the first string where second string occurs last time. If it does not contain, return "-1"
### Expected function
```go
package main
Refactor & Beautify & destruction commit
return early, remove else branches, reorder conditions and top-level functions, remove empty lines, remove unnecessary append(), fix typos, stop using testing package, remove dead code, fix mistakes in subjects, tests and solutions, remove disclaimers, reformat comments, simplify solutions, tests, add more instructions to subjects, remove obsolete files, etc.
Some of the reasons behind those modifications will be added to good-practices.en.md
Some of the exercises are now broken, they will have to be fixed, most of them have a "TODO:" comment.
5 years ago
func DoppelGanger(s, substr string) int {
}
```
```go
package main
import (
"fmt"
piscine ".."
)
func main() {
var result int
result = piscine.DoppelGanger("aaaaaaa", "a")
fmt.Println(result) // 6
result = piscine.DoppelGanger("qwerty", "t")
fmt.Println(result) // 4
result = piscine.DoppelGanger("a", "b")
fmt.Println(result) // -1
}
```
