Problem: You are given a function f written in some basic language. The function accepts an integer value, which is immediately written into some variable x. x is an integer variable and can be assigned values from 0 to 2^{32}-1. The function contains three types of commands:

  * for n — for loop; 
  * end — every command between "for n" and corresponding "end" is executed n times; 
  * add — adds 1 to x. 



After the execution of these commands, value of x is returned.

Every "for n" is matched with "end", thus the function is guaranteed to be valid. "for n" can be immediately followed by "end"."add" command can be outside of any for loops.

Notice that "add" commands might overflow the value of x! It means that the value of x becomes greater than 2^{32}-1 after some "add" command. 

Now you run f(0) and wonder if the resulting value of x is correct or some overflow made it incorrect.

If overflow happened then output "OVERFLOW!!!", otherwise print the resulting value of x.

Input

The first line contains a single integer l (1 ≤ l ≤ 10^5) — the number of lines in the function.

Each of the next l lines contains a single command of one of three types:

  * for n (1 ≤ n ≤ 100) — for loop; 
  * end — every command between "for n" and corresponding "end" is executed n times; 
  * add — adds 1 to x. 

Output

If overflow happened during execution of f(0), then output "OVERFLOW!!!", otherwise print the resulting value of x.

Examples

Input


9
add
for 43
end
for 10
for 15
add
end
add
end


Output


161


Input


2
for 62
end


Output


0


Input


11
for 100
for 100
for 100
for 100
for 100
add
end
end
end
end
end


Output


OVERFLOW!!!

Note

In the first example the first "add" is executed 1 time, the second "add" is executed 150 times and the last "add" is executed 10 times. Note that "for n" can be immediately followed by "end" and that "add" can be outside of any for loops.

In the second example there are no commands "add", thus the returning value is 0.

In the third example "add" command is executed too many times, which causes x to go over 2^{32}-1.

Solution (in JAVA):

Solution:
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Scanner;
import java.util.StringTokenizer;
import java.util.*;
public class Main
{
  static boolean prime[] = new boolean[1000001];
  static int parent[];
    static class FastReader
    {
        BufferedReader br;
        StringTokenizer st;

        public FastReader()
        {
            br = new BufferedReader(new
                     InputStreamReader(System.in));
        }

        String next()
        {
            while (st == null || !st.hasMoreElements())
            {
                try
                {
                    st = new StringTokenizer(br.readLine());
                }
                catch (IOException  e)
                {
                    e.printStackTrace();
                }
            }
            return st.nextToken();
        }

        int nextInt()
        {
            return Integer.parseInt(next());
        }

        long nextLong()
        {
            return Long.parseLong(next());
        }

        double nextDouble()
        {
            return Double.parseDouble(next());
        }

        String nextLine()
        {
            String str = "";
            try
            {
                str = br.readLine();
            }
            catch (IOException e)
            {
                e.printStackTrace();
            }
            return str;
        }
    }
  static  void sieveOfEratosthenes(int n)
 {
     // Create a boolean array "prime[0..n]" and initialize
     // all entries it as true. A value in prime[i] will
     // finally be false if i is Not a prime, else true.

     for(int i=0;i<n;i++)
         prime[i] = true;

     for(int p = 2; p*p <=n; p++)
     {
         // If prime[p] is not changed, then it is a prime
         if(prime[p] == true)
         {
             // Update all multiples of p
             for(int i = p*2; i <= n; i += p)
                 prime[i] = false;
         }
     }

 }

    static long power(long x, long y, long p)
       {

           long res = 1;

           // Update x if it is more
           // than or equal to p
           x = x %p;

           while (y > 0)
           {
               // If y is odd, multiply x
               // with result
               if((y & 1)==1)
                   res = (res * x) %p;

               // y must be even now
               // y = y / 2
               y = y >> 1;
               x = (x * x)%p ;
           }
           return res;
       }
       static long fun(long n, long r) {

        // p holds the value of n*(n-1)*(n-2)...,
        // k holds the value of r*(r-1)...
        long p = 1, k = 1;

        // C(n, r) == C(n, n-r),
        // choosing the smaller value
        if (n - r < r) {
            r = n - r;
        }

        if (r != 0) {
            while (r > 0) {
                p *= n;
                k *= r;

                // gcd of p, k
                long m = __gcd(p, k);

                // dividing by gcd, to simplify product
                // division by their gcd saves from the overflow
                p /= m;
                k /= m;

                n--;
                r--;
            }

            // k should be simplified to 1
            // as C(n, r) is a natural number
            // (denominator should be 1 ) .
        } else {
            p = 1;
        }

        // if our approach is correct p = ans and k =1
        return p;
    }

    static long __gcd(long n1, long n2) {
        long gcd = 1;

        for (int i = 1; i <= n1 && i <= n2; ++i) {
            // Checks if i is factor of both integers
            if (n1 % i == 0 && n2 % i == 0) {
                gcd = i;
            }
        }
        return gcd;
    }


    public static void main(String[] args)
    {
        FastReader sc=new FastReader();

/*
9
add
for 43
end
for 10
for 15
add
end
add
end
*/
        int t=sc.nextInt();
        //HashMap<Long,Long> hm=new HashMap<>();
        Stack<Long> st=new Stack<>();
        long count=0;
        long x=0;
        while(t-->0)
        {
          String str=sc.next();
          if(str.equals("add"))
          {
            if(st.isEmpty())
            {
              x+=1;
            }
            else
            {
            x+=st.peek();
            }
          }
          if(str.equals("for"))
          {
            long p=sc.nextLong();
            if(st.isEmpty())
            {
              st.push(p);

            }
            else
            {
              st.push(Math.min((long)Math.pow(2,32),st.peek()*p));
            }
            count++;
          }
          if(str.equals("end"))
          {

            st.pop();

          }

        }
        if(x>=Math.pow(2,32)||x<0)
        {
          System.out.println("OVERFLOW!!!");
        }
        else
        {
          System.out.println(x);
        }
    }
}
class MergeSort
{
    // Merges two subarrays of arr[].
    // First subarray is arr[l..m]
    // Second subarray is arr[m+1..r]
    void merge(long arr[], int l, int m, int r)
    {
        // Find sizes of two subarrays to be merged
        int n1 = m - l + 1;
        int n2 = r - m;

        /* Create temp arrays */
        long L[] = new long [n1];
        long R[] = new long [n2];

        /*Copy data to temp arrays*/
        for (int i=0; i<n1; ++i)
            L[i] = arr[l + i];
        for (int j=0; j<n2; ++j)
            R[j] = arr[m + 1+ j];


        /* Merge the temp arrays */

        // Initial indexes of first and second subarrays
        int i = 0, j = 0;

        // Initial index of merged subarry array
        int k = l;
        while (i < n1 && j < n2)
        {
            if (L[i] <= R[j])
            {
                arr[k] = L[i];
                i++;
            }
            else
            {
                arr[k] = R[j];
                j++;
            }
            k++;
        }

        /* Copy remaining elements of L[] if any */
        while (i < n1)
        {
            arr[k] = L[i];
            i++;
            k++;
        }

        /* Copy remaining elements of R[] if any */
        while (j < n2)
        {
            arr[k] = R[j];
            j++;
            k++;
        }
    }

    // Main function that sorts arr[l..r] using
    // merge()
    void sort(long arr[], int l, int r)
    {
        if (l < r)
        {
            // Find the middle point
            int m = (l+r)/2;

            // Sort first and second halves
            sort(arr, l, m);
            sort(arr , m+1, r);

            // Merge the sorted halves
            merge(arr, l, m, r);
        }
    }

    /* A utility function to print array of size n */
    static void printArray(int arr[])
    {
        int n = arr.length;
        for (int i=0; i<n; ++i)
            System.out.print(arr[i] + " ");
        System.out.println();
    }
}