#include <bits/stdc++.h>

#include <ext/pb_ds/assoc_container.hpp>

#include <ext/pb_ds/tree_policy.hpp>

using namespace std;

using namespace __gnu_pbds;

typedef long long ll ;

typedef vector<ll> vl;

#define speed cin.tie(0);cout.tie(0);ios_base::sync_with_stdio(0);

#define phi 1.618

#define ff first

#define ss second

#define mp make_pair

#define line cout<<endl;

#define pb push_back

#define Endl "\n"

#define forin(arr,n) for(ll i=0;i<n;i++) cin>>arr[i];

#define no cout<<"NO"<<endl;

#define yes cout<<"YES"<<endl;

#define cc ll test;cin>>test;while(test--)

#define all(V) (V).begin(),(V).end()

#define srt(V) sort(all(V))

#define srtGreat(V) sort(all(V),greater<ll>())

#define printv(v) for(ll i=0;i<ll(v.size());i++){cout<<v[i]<<" ";} line;

ll power(ll x,ll y,ll mod)

{

ll res=1;

// x=x%mod;

while(y>0)

{

if(y%2==1)

{

res*=x;

// res=res%mod;

}

y/=2; x*=x; // x=x%mod;

}

return res;

}

#define ordered_set tree<ll,null_type,less<ll>,rb_tree_tag,tree_order_statistics_node_update>

ll solve()

{

cout<<"No of operation "<<;

ll q;

cin>>q;

stack<pair<ll,ll>> st;

ll maxo=0;

while(q--)

{

cout<<"1.for updation\n2.pop top element\n3.maximum element in stack"<<endl;

ll a;

cin>>a;

if(a==1)

{

ll x;

cout<<"enter element ";

cin>>x;

if(st.size()>0)

st.push({x,max(st.top().ss,x)});

else

st.push({x,max(0LL,x)});

}

else if(a==2)

st.pop();

else

cout<<st.top().ss<<endl;

}

return 0;

}

int main()

{

speed;

//freopen("input.txt"a, "r", stdin);

solve();

}