def min_operations(s):
    n = len(s)
    result = 0
    
    for i in range(n):
        zeros = ones = 0
        for j in range(i, n):
            if s[j] == '0':
                zeros += 1
            else:
                ones += 1
            
            if j > i and zeros >= ones:
                result = max(result, zeros - ones + 1)
    
    if result > s.count('0'):
        return -1
    
    return result