Does anyone know why i keep getting this wrong:

import math import os import random import re import sys

words = {}

if name == 'main': s = input()

for x in range(len(s) - 1, -1, -1):
    if s[x] not in words:
        words[s[x]] = 1
    else:
        words[s[x]] += 1

# Sort the dictionary by frequency (ascending)
fixed = sorted(words.items(), key=lambda item: item[1])

# Display the sorted results
for char, freq in fixed:
    print(f"{char} {freq}")