static void Main(string[] args)
{
Solution sln = new Solution();
int r = sln.Calculate(@"1 -( 20-( -15) )-40");
Calculator c = new Calculator();
// var m = c.Calculate("1+2*5/3+6/4*2");
Calculator2 calci = new Calculator2();
// string ho = "(1+(4+5+2)-3)+(6+8)";
string ho = " 2-1 + 2 ";
int what = calci.Calculate(ho);
Stack <int> st = new Stack <int>();
CustomStack s = new CustomStack();
s.Push(9);
s.Push(5);
s.Push(7);
s.Push(1);
s.Push(2);
int peek = s.Peek();
int min = s.Min();
s.Pop();
min = s.Peek();
s.Pop();
min = s.Min();
peek = s.Peek();
Console.WriteLine();
}