암호:
#include <bits/stdc++.h>
using namespace std;
int n, m;
int a[109];
void _pop () {
a[m--] = 0;
}
void _push () {
cin >> a[++m];
}
int _size () {
return m;
}
int _top () {
return a[m];
}
int main () {
cin >> n;
for (int i = 1; i <= n; i++)
_push();
cout << _size() << " " << _top() << endl;
_pop();
cout << _size() << " " << _top();
return 0;
}