acids$=\{\text{'}$UUU$\text{'}$: $\{\text{'}1-$letter': $\text{'}$F$\text{'},\text{'}3-$letter': 'Phe', 'amino acid': 'Phenylalanine'$\}\}$

$\{\text{'}$UUC$\text{'}$: $\{\text{'}1-$letter': $\text{'}$F$\text{'},\text{'}3-$letter': 'Phe', 'amino acid': 'Phenylalanine'$\}\}$

$\{\text{'}$UUA$\text{'}$: $\{\text{'}1-$letter': $\text{'}$L$\text{'},\text{'}3-$letter': 'Leu', 'amino acid': 'Leucine'$\}\}$

$\{\text{'}$UUG$\text{'}$: $\{\text{'}1-$letter': $\text{'}$L$\text{'},\text{'}3-$letter': 'Leu', 'amino acid': 'Leucine'$\}\}$

$......$

$\{\text{'}$GGG$\text{'}$: $\{\text{'}1-$letter': $\text{'}$G$\text{'},\text{'}3-$letter': $\text{'}$Gly$\text{'},$ 'amino acid': 'Glycine'$\}\}$

# create an empty string variable called 'protein

# Find the index of the 'AUG' substring in the mrna variable from Part $3$

start$\_$codon$=$ mrna.find$(\text{'}$AUG$\text{'})$

# create a loop counter variable that starts at this index

index$=$ start$\_$codon

# Create a 'while' loop to iterate while the loop counter is less than the length of the mrna string

while index$<$ len$($mrna$)$:

# Using the loop counter as the index into the mrna string, grab the next triplet $($mrna$[$idx:idx$+3])$ and store in a variable called 'triplet'

triplet$=$ mrna$[$index:index$+3]$

# Using this 'triplet' string variable as a key, look up the $\text{'}1-$letter' protein associated with it using the acids dictionary$-----$HELP here

# If this is equal to $\text{'}$X$\text{'},$ break out of the loop

# if not, add this letter to the protein string

# Add $3$ to the counter variable

index $+=3$