n=int(input())
stack_in=[]
stack_out=[]

def transfer():
    while stack_in:
        stack_out.append(stack_in.pop())

for _ in range(n):
    arr=input().split(' ')
    if arr[0]=='1':
        stack_in.append(int(arr[1]))        
    elif arr[0]=='2':
        if not stack_out: 
            transfer()
        if stack_out: 
            stack_out.pop()
    else:
        if not stack_out: 
            transfer()
        if stack_out: 
            print(stack_out[-1])