#include <bits/stdc++.h> #include <functional> using namespace std; vector<int> v; int main() { int q,op,x,i; cin >> q; for (int j=0;j<q;j++) { cin >> op; switch (op) { case 1: cin >> x; v.push_back(x); break; case 2: v.pop_back(); break; case 3: cin >> i...