from datetime import datetime, timedelta
import calendar

def get_last_friday(month_year: str) -> str:
    month, year = map(int, month_year.split('/'))
    last_day = calendar.monthrange(year, month)[1] 
    date_obj = datetime(year, month, last_day)
    offset = (date_obj.weekday() - 4) % 7
    last_friday = date_obj - timedelta(days=offset)
    return last_friday.strftime("%d.%m.%Y")