水题

#include<bits/stdc++.h>
using namespace std;
int path[100000];
int t,num,car,i;
void search(int []){
	int ans=0;
	for(int j=0;j<i;j++)
	{
		if(path[j] > ans)
			ans = path[j];	
	}
	if(ans == 0)
		cout<<-1<<endl;
	else
		cout<<ans<<endl;
}
int main() {
	std::ios::sync_with_stdio(false);
	cin>>t;
	while(t--){
		stack<int> cnt;
		cin>>num;
		if(num == 1){
			cin>>car;
			path[i++] = car;
			cnt.push(car);
		}
		else if(num == 2){
			cnt.pop();
			i--;
			path[i]=0;
		}
		else
			search(path);
	}
    return 0; 
}