最小栈

def solve():
    class MinStack:
        def __init__(____):
            self.stack = []
            self.min_stack = []
        
        def push(____):
            self.stack.append(____)
            if not self.min_stack or x <= self.min_stack[-____]:
                self.min_stack.append(____)
            else:
                self.min_stack.append(____)
        
        def pop(____):
            self.stack.pop()
            self.min_stack.pop()
        
        def get_min(____):
            return self.min_stack[-____]
    
    ms = MinStack()
    ms.push(____)
    ms.push(____)
    ms.push(____)
    result = [str(ms.get_min())]
    ms.pop()
    result.append(str(ms.get_min()))
    print('____'.join(____))