public static void Main()
Console.WriteLine("Enter the arithmetic expression.");
string expression = Console.ReadLine();
int parenthesis1 = expression.IndexOf("(");
int numberOfParenthesis1 = 0;
int parenthesis2 = expression.IndexOf(")");
int numberOfParenthesis2 = 0;
while (parenthesis1 != -1 && parenthesis2 != -1)
parenthesis1 = expression.IndexOf("(", parenthesis1 + 1);
Console.WriteLine(parenthesis1);
parenthesis2 = expression.IndexOf(")", parenthesis2 + 1);
Console.WriteLine(parenthesis2);
if (parenthesis2 < parenthesis1)
Console.WriteLine("Parentheses are placed incorrectly");
if (numberOfParenthesis1 != numberOfParenthesis2)
Console.WriteLine("Parentheses are placed incorrectly");