Minimize Parentheses Reversals

You are given a string consisting of only '{' and '}'. Your task is to determine the minimum number of reversals (changes '{' to '}' or vice versa) needed to make the string balanced. A string is balanced if: 1. Each opening brace has a corresponding closing brace. 2. No closing brace occurs without a matching opening brace preceding it. Return -1 if it is impossible to balance the string. Implement a function that reads from standard input and prints the minimum number of reversals or -1 if balancing is impossible. ### Example: Input: {{{}{{ Output: 3 ### Input format: A single line string containing only '{' and '}'. Maximum length is 100. ### Output format: An integer representing minimum number of reversals or -1.