#include <bits/stdc++.h>   using namespace std;   using ll = long long;   using ld = long double;   using db = double;   using str = string;   using pi = pair<int, int>;   using pl = pair<ll, ll>;   using pd = pair<db, db>;   using vi = vector<int>;   using vb = vector<bool>;   using vl = vector<ll>;   using vd = vector<db>;   using vs = vector<str>;   using vpi = vector<pi>;   using vpl = vector<pl>;   using vpd = vector<pd>;   template <class T>   using V = vector<T>;   template <class T, size_t SZ>   using AR = array<T, SZ>;   const int MOD = 1e9 + 7;   const int MX = 2e5 + 5;   const ll INF = 1e18;   const ld PI = acos((ld)-1);   const int xd[4] = {1, 0, -1, 0}, yd[4] = {0, 1, 0, -1};   mt19937 rng((uint32_t)chrono::steady_clock::now().time_since_epoch().count());   constexpr int pct(int x) { return __builtin_popcount(x); }   constexpr int bits(int x) { return 31 - __builtin_clz(x); }   ll cdiv(ll a, ll b) { return a / b + ((a ^ b) > 0 && a % b); }   ll fdiv(ll a, ll b) { return a / b - ((a ^ b) < 0 && a % b); }   template <class T>   bool ckmin(T& a, const T& b) {     return b < a ? a = b, 1 : 0;   }   template <class T>   bool ckmax(T& a, const T& b) {     return a < b ? a = b, 1 : 0;   }   template <class T, class U>   T fstTrue(T lo, T hi, U first) {     hi++;     assert(lo <= hi);     while (lo < hi) {       T mid = lo + (hi - lo) / 2;       first(mid) ? hi = mid : lo = mid + 1;     }     return lo;   }   template <class T, class U>   T lstTrue(T lo, T hi, U first) {     lo--;     assert(lo <= hi);     while (lo < hi) {       T mid = lo + (hi - lo + 1) / 2;       first(mid) ? lo = mid : hi = mid - 1;     }     return lo;   }   template <class T>   void remDup(vector<T>& v) {     sort(begin(v), end(v));     v.erase(unique(begin(v), end(v)), end(v));   }   template <class T, class U>   void erase(T& t, const U& u) {     auto it = t.find(u);     assert(it != end(t));     t.erase(u);   }   template <class T>   void re(complex<T>& c);   template <class T, class U>   void re(pair<T, U>& p);   template <class T>   void re(vector<T>& v);   template <class T, size_t SZ>   void re(AR<T, SZ>& a);   template <class T>   void re(T& x) {     cin >> x;   }   void re(db& d) {     str t;     re(t);     d = stod(t);   }   void re(ld& d) {     str t;     re(t);     d = stold(t);   }   template <class T, class... U>   void re(T& t, U&... u) {     re(t);     re(u...);   }   template <class T>   void re(complex<T>& c) {     T a, b;     re(a, b);     c = {a, b};   }   template <class T, class U>   void re(pair<T, U>& p) {     re(p.first, p.second);   }   template <class T>   void re(vector<T>& x) {     for (auto& a : x) re(a);   }   template <class T, size_t SZ>   void re(AR<T, SZ>& x) {     for (auto& a : x) re(a);   }   str to_string(char c) { return str(1, c); }   str to_string(const char* second) { return (str)second; }   str to_string(str second) { return second; }   str to_string(bool b) { return to_string((int)b); }   template <class T>   str to_string(complex<T> c) {     stringstream ss;     ss << c;     return ss.str();   }   str to_string(vector<bool> v) {     str res =  { ;     for (int i = (0); i < ((int)(v).size()); ++i) res += char( 0  + v[i]);     res +=  } ;     return res;   }   template <size_t SZ>   str to_string(bitset<SZ> b) {     str res =   ;     for (int i = (0); i < (SZ); ++i) res += char( 0  + b[i]);     return res;   }   template <class T, class U>   str to_string(pair<T, U> p);   template <class T>   str to_string(T v) {     bool fst = 1;     str res =   ;     for (const auto& x : v) {       if (!fst) res +=    ;       fst = 0;       res += to_string(x);     }     return res;   }   template <class T, class U>   str to_string(pair<T, U> p) {     return to_string(p.first) +     + to_string(p.second);   }   template <class T>   void pr(T x) {     cout << to_string(x);   }   template <class T, class... U>   void pr(const T& t, const U&... u) {     pr(t);     pr(u...);   }   void ps() { pr(  n ); }   template <class T, class... U>   void ps(const T& t, const U&... u) {     pr(t);     if (sizeof...(u)) pr(   );     ps(u...);   }   void DBG() { cerr <<  ]  << endl; }   template <class T, class... U>   void DBG(const T& t, const U&... u) {     cerr << to_string(t);     if (sizeof...(u)) cerr <<  ,  ;     DBG(u...);   }   void setIn(str second) { freopen(second.c_str(),  r , stdin); }   void setOut(str second) { freopen(second.c_str(),  w , stdout); }   void unsyncIO() { cin.tie(0)->sync_with_stdio(0); }   void setIO(str second =   ) {     unsyncIO();     if ((int)(second).size()) {       setIn(second +  .in ), setOut(second +  .out );     }   }   int main() {     setIO();     int l;     cin >> l;     ll num = 0;     vl v;     v.push_back(1);     for (int a = (0); a < (l); ++a) {       string second;       cin >> second;       if (second ==  add ) {         num += v.back();         if (num > 4294967295) {           cout <<  OVERFLOW!!!  << endl;           return 0;         }       } else if (second ==  for ) {         int k;         cin >> k;         v.push_back(min(4294967296LL, k * v.back()));       } else         v.pop_back();     }     cout << num << endl;   }