list_index_deg = []
for i in range(len(str) ):
    if str[i] == '^':
        list_index_deg.append(i)


for index in list_index_deg:
    if str[index - 1].islower():
        expression = str[index - 1]
    if str[index - 1] == ')':
        count = 0
        expression = ''
        copy_index = index
        while count >= 0 and copy_index >= 0:
            if str[copy_index] == ')':
                count += 1
            if str[copy_index] == '(':
                count -= 1
            expression = str[copy_index] + expression
            copy_index -= 1
    expression = expression[:-1]