`Medium`	`Codewriting` 	`300`

Given a string, find the number of different characters in it.

## Example

- For `s = "cabca"`, the output should be
`differentSymbolsNaive(s) = 3`.

There are 3 different characters a, b and c.

## Input/Output

- [execution time limit] 4 seconds (go)

- [input] string s

    A string of lowercase English letters.

    Guaranteed constraints: \
    `3 ≤ s.length ≤ 1000`.

- [output] integer

## [Go] Syntax Tips

``` go
// Prints help message to the console
// Returns a string
func helloWorld(name string) string {
    fmt.Printf("This prints to the console when you Run Tests");
    return "Hello, " + name;
}
```
