#include <stdio.h>
#include <stdlib.h>

struct stack
{
    int *arr;
    int size;
    int top;
};

int isEmpty(struct stack *s)
{
    if(s->top == -1)
        return 1;
    return 0;
}

int isFull(struct stack *s)
{
    if(s->top == s->size - 1)
        return 1;
    return 0;
}

void push(struct stack *s, int data)
{
    if(!isFull(s))
    {
        s->top++;
        s->arr[s->top] = data;
    }
    else {
        printf("Stack overflow\n");
    }
}

int pop(struct stack *s)
{
    int ans = -1;
    if(isEmpty(s))
        printf("Stack underflow\n");
    else {
        ans = s->arr[s->top];
        s->top--;
    }
    return ans;
}

int maximum(struct stack *s)
{
    int max = s->arr[0];
    for(int i = 0; i <= s->top; i++)
    {
        if(max < s->arr[i])
            max = s->arr[i];
    }
    return max;
}

int main()
{
    int query;
    scanf("%d",&query);
    struct stack *s = (struct stack *)malloc(sizeof(struct stack));
    s->size = query + 1;
    s->top = -1;
    s->arr = (int *)malloc(s->size * sizeof(int));
    for(int i = 0; i < query; i++)
    {
        int type;
        scanf("%d",&type);
        if(type == 1)
        {
            int data;
            scanf("%d",&data);
            push(s,data);
        }
        else if(type == 2)
        {
            pop(s);
        }
        else
        {
            int max = maximum(s);
            printf("%d\n",max);
        }
    }
}

def getMax(operations):
    stack = [0]
    my = []
    for i in operations:
        if int(i[0]) == 1:
            n = int(i[2:])
            stack.append(max(n,stack[-1]))
        elif int(i[0]) == 2:
            if stack:
                stack.pop()
        else:
            my.append(stack[-1])
    return my

public static List<Integer> getMax(List<String> operations) {
        List<Integer> op = new ArrayList<>();
        Stack<Integer> mainStack = new Stack<>();
        Stack<Integer> maxStack = new Stack<>();
        for(String s : operations){
            if(s.startsWith("1")){
                String[] ss = s.split(" ");
                Integer x = Integer.valueOf(ss[1]);
                //System.out.println(x);
                mainStack.push(x);
                if(maxStack.isEmpty() || x > maxStack.peek()){               
                    maxStack.push(x);            
                }else{
                    maxStack.push(maxStack.peek());
                }
                System.out.println("X "+x+" Max "+maxStack.peek());   
            }else if(s.equals("2")){
                mainStack.pop();
                maxStack.pop(); 
            }else{
                op.add(maxStack.peek());
            }
        }
    return op;
    }

}

#include <bits/stdc++.h>

using namespace std;

int main(){
    int n;
    cin>>n;
    stack<int> s;
    stack<int> maxStack;
    while(n--){
        int a,b;
        cin>>a;
        if(a==1){
            cin>>b;
        }
        if(a==1){
            s.push(b);
            if(maxStack.empty()){
                maxStack.push(b);
            }
            else{
                maxStack.push(max(maxStack.top(),b));
            }
        }
        else if(a==2){
            s.pop();
            maxStack.pop();
        }
        else{
            cout<<maxStack.top()<<endl;
        }
    }
}

def getMax(operations):
    # Write your code here
    stack = list()
    sorted_stack = []
    answer = []
    for i in range(len(operations)):
        query = list(map(int, operations[i].split()))
        if query[0] == 1:
            stack.append(query[1])
            sorted_stack.append(query[1])
            sorted_stack.sort()
        elif query[0] == 2:
            sorted_stack.remove(stack.pop())
        else:
            answer.append(sorted_stack[-1])
    return answer