mapping={
    '2':'abc',
    '3':'def',
    '4':'ghi',
    '5':'jkl',
    '6':'mno',
    '7':'pqrs',
    '8':'tuv',
    '9':'wxyz',
}
def letter_combinationss(digits):
if not digits:
return=[]

result=[]

def backtrack(index,current_combination):
if index == len(digits):
result.append(current_combination)
return
current_digit = digits[index]
if current_digit = digits[index]
if crrent_digit in mapping:
for letter in
mappin[current_digit]:
backtrack(index + 1,current_combination + letter)

backtrack(0,"")
return result
#sample input 1:"2"
input1 = "2"
ouutput1 = letter_combinations(input1)
#print(f"Input:{input}, Output:{output}")

#sample Input 2: "23" (from problem description example)
input2 = "23"
output2 = letter_combinations(input2)
#print(f"Input:{Input2},Output:{output2}")