def nome_usuario(email):
    i = 0
    palavra = 'aa'
    while i < len(email):
        if email[i] == "@":
            return email[:i]
        i+=1
    
41049140ef6f407c0040c4a20f959cd8fd1d7c69
<mask token>

def nome_usuario(email):
    i = 0
    palavra = 'aa'
    while i < len(email):
        if email[i] == '@':
            return email[:i]
        i += 1

def nome_usuario(email):
    i = 0
    palavra = 'aa'
    while i < len(email):
        if email[i] == "@":
            return email[:i]
        i+=1
    