def find_length(string, n):
	 
	current_sum = 0
	max_sum = 0
	for i in range(n): 
		current_sum += (1 if string[i] == '0' else -1) 
		if current_sum < 0: 
			current_sum = 0
		max_sum = max(current_sum, max_sum) 
	return max_sum if max_sum else 0
def find_length(string, n):
    VAR_0 = 0
    max_sum = 0
    for i in range(n):
       
        VAR_0 += 1 if string[i] == "0" else -1
        if VAR_0 < 0:
            VAR_0 = 0
        max_sum = max(VAR_0, max_sum)
    return max_sum if max_sum else 0