For example, I have a dict and I want to use the string `"apple"` and return the corresponding values in the dictionary of every given letter in the string:

```none
'dot-dash-dot-dash-dash-dot-dot-dash-dash-dot-dot-dash-dot-dot-dot'

```

```
morse_dict = {
    'a': 'dot-dash',
    'b': 'dash-dot-dot-dot',
    'c': 'dash-dot-dash-dot',
    'd': 'dash-dot-dot',
    'e': 'dot',
    'f': 'dot-dot-dash-dot',
    'g': 'dash-dash-dot',
    'h': 'dot-dot-dot-dot',
    'i': 'dot-dot',
    'j': 'dot-dash-dash-dash',
    'k': 'dash-dot-dash',
    'l': 'dot-dash-dot-dot',
    'm': 'dash-dash',
    'n': 'dash-dot',
    'o': 'dash-dash-dash',
    'p': 'dot-dash-dash-dot',
    'q': 'dash-dash-dot-dash',
    'r': 'dot-dash-dot',
    's': 'dot-dot-dot',
    't': 'dash',
    'u': 'dot-dot-dash',
    'v': 'dot-dot-dot-dash',
    'w': 'dot-dash-dash',
    'y': 'dash-dot-dash-dash',
    'z': 'dash-dash-dot-dot'
}

a = tuple("word")
for x in a:
    return("-".join([val for keys, val in morse_dict.items() if x in keys]))

```

What am I doing wrong here?