External excercise 1b 

sss = 'toi la aia' 
char = ''
for i in range(0, len(sss)):
    if sss[i]==' ':
      continue
    if sss[i] in sss[0:i]:
        continue
    char = char + ' ' + sss[i]+ ':' + str(sss.count(sss[i]))
print(char)