from typing import Dict


def freq_dict_to_lowercase(input_dict: Dict[str, int]) -> Dict[str, int]:
    """Takes a dictionary of string to value, and returns one where the keys are all mapped to
    lowercase and the values are the sums of all the values mapped in this way."""
    output_dict = {}
    for item in input_dict.items():
        lc = item[0].lower()
        output_dict[lc] = output_dict.get(lc, 0) + item[1]
    return output_dict