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.*;
import java.util.*;
import java.util.Queue;
import java.util.LinkedList;
import java.util.Stack;

public class Main
{
      @SuppressWarnings("unchecked")
      public static void main(String args[])throws IOException
    {
         Reader ob=new Reader();
        Writer out=new Writer(System.out);
        Random oo=new Random();
       int t=ob.nI();long x1=0,max=pow(2,32)-1;long p=1,q=0;
       Stack<Integer> st=new Stack();
       while(t-->0)
       {
           String x=ob.n();
           if(x.equals("for"))
           {
               int h=ob.nI();
               if(p<=2*max)
               {
               st.push(h);
               p*=st.peek();
            }
            else
            {
                q++;
            }
            }
            else if(x.equals("add"))
            {
                if(st.isEmpty())
                x1++;
                else
                {
                    if(q>0)
                    {
                        out.p("OVERFLOW!!!");
                        x1=2*max;
                break; 
                    }
                    else
                    x1+=p;
                }
                
            }
            else
            {
                if(q>0)
                q--;
                else if(!st.isEmpty())
                p/=st.pop();
                
            }
            if(x1>max)
            {
                out.p("OVERFLOW!!!");
                break;
            }
        }
        if(x1<=max)
        out.p(x1);
out.flush();
}
static void sort(int a[])
{
    RA(a);
    Arrays.sort(a);
}
 public static Pairs[] RA(Pairs [] array){
		Random rgen = new Random();  // Random number generator			
 
		for (int i=0; i<array.length; i++) {
		    int randomPosition = rgen.nextInt(array.length);
		    Pairs temp = array[i];
		    array[i] = array[randomPosition];
		    array[randomPosition] = temp;
		}
 
		return array;
	}
	
 public static int[] RA(int [] array){
		Random rgen = new Random();  // Random number generator			
 
		for (int i=0; i<array.length; i++) {
		    int randomPosition = rgen.nextInt(array.length);
		    int temp = array[i];
		    array[i] = array[randomPosition];
		    array[randomPosition] = temp;
		}
 
		return array;
	}
	static void sort(long a[])
{
    RA(a);
    Arrays.sort(a);
}
 public static long[] RA(long [] array){
		Random rgen = new Random();  // Random number generator			
 
		for (int i=0; i<array.length; i++) {
		    int randomPosition = rgen.nextInt(array.length);
		    long temp = array[i];
		    array[i] = array[randomPosition];
		    array[randomPosition] = temp;
		}
 
		return array;
	}
	static void sort(String a[])
{
    RA(a);
    Arrays.sort(a);
}
 public static String[] RA(String [] array){
		Random rgen = new Random();  // Random number generator			
 
		for (int i=0; i<array.length; i++) {
		    int randomPosition = rgen.nextInt(array.length);
		    String temp = array[i];
		    array[i] = array[randomPosition];
		    array[randomPosition] = temp;
		}
 
		return array;
	}
static long inverse(long x, long p)
    {
        return pow(x, p - 2, p);
    }
static boolean isPrime(long n)
{
    long h=(long)Math.sqrt(n);
    for(long i=2;i<=h;i++)
    if(n%i==0)
    return false;
    return true&&n!=1;
}
    static long gcd(long a,long b)
    {
        if(a<b)
        return gcd(b,a);
        else if(b==0)
        return a;
        else
        return gcd(b,a%b);
    }
    static long pow(long a,long b,long mod){
		if(b == 0)	return 1;
		long t = pow(a,b>>1,mod);
		t = (t * t) % mod;
		if((b & 1) == 1)	t = (t * a);
		if(t >= mod)	t %= mod;
		return t;
}
    static long pow(long a,long b){
		if(b == 0)	return 1;
		long t = pow(a,b>>1);
		t = (t * t);
		if((b & 1) == 1)	t = (t * a);
		return t;
}
    static void seive(int n,int prime[])//smallest factor greater than 1
    {
        for(int i=2;i<=n;i++)
            if(prime[i]==0)
            {
                prime[i]=i;
                for(int j=i;j*i<=n;j++)
                if(prime[j*i]==0)
                prime[j*i]=i;
            }
    }
    static int max(int ...a)
    {
        int m=a[0];
        for(int i=0;i<a.length;i++)
        m=Math.max(m,a[i]);
        return m;
        
    }
    static long max(long ...a)
    {
        long m=a[0];
        for(int i=0;i<a.length;i++)
        m=Math.max(m,a[i]);
        return m;
    }
    static int min(int ...a)
    {
        int m=a[0];
        for(int i=0;i<a.length;i++)
        m=Math.min(m,a[i]);
        return m;
    }
    static long min(long ...a)
    {
        long m=a[0];
        for(int i=0;i<a.length;i++)
        m=Math.min(m,a[i]);
        return m;
    }
    static class Pair<T1,T2>
    {
        T1 x;T2 y;
        Pair(T1 xx,T2 yy)
        {
            x=xx;
            y=yy;
        }
    }
    
	static class Writer {
		private final PrintWriter p;
		Writer(OutputStream o) {
			p = new PrintWriter(new BufferedWriter(new OutputStreamWriter(o)));
		}
		void p(Object... o1) {
			for (Object o11 : o1) {
				p.print(o11 + "" );
			}
		}
		<T>void pa(T a[])
		{
		    for(T i:a)
		    System.out.print(i+" ");
		    System.out.println();
		  }
		void p(String s) {
			p.print(s);
		}
		void pln(Object... o1) {
			p(o1);
			p.println();
		}
		void flush() {
			p.flush();
		}
		void close() {
			p.close();
		}
	}
    static class Reader {
		private byte[] buf = new byte[1024];
		private int curChar;
		private int snumChars;
		int flag=0;
		FileReader file;
		Reader()
		{
		  }
		  Reader(String x)throws IOException
		  {
		      flag=1;
		      file=new FileReader(x);
		  }
		public int read() {
			if (snumChars == -1)
				throw new InputMismatchException();
			if (curChar >= snumChars) {
				curChar = 0;
				try {
					snumChars = System.in.read(buf);
				
				} catch (IOException e) {
					throw new InputMismatchException();
				}
				if (snumChars <= 0)
					return -1;
			}
			return buf[curChar++];
		}
		public String nl() {
			int c = read();
			while (isSpaceChar(c))
				c = read();
			StringBuilder res = new StringBuilder();
			do {
				res.appendCodePoint(c);
				c = read();
			} while (!isEndOfLine(c));
			return res.toString();
		}
		public String n() {
			int c = read();
			while (isSpaceChar(c))
				c = read();
			StringBuilder res = new StringBuilder();
			do {
				res.appendCodePoint(c);
				c = read();
			} while (!isSpaceChar(c));
			return res.toString();
		}
		public long nL() {
			int c = read();
			while (isSpaceChar(c))
				c = read();
			int sgn = 1;
			if (c == '-') {
				sgn = -1;
				c = read();
			}
			long res = 0;
			do {
				if (c < '0' || c > '9')
					throw new InputMismatchException();
				res *= 10;
				res += c - '0';
				c = read();
			} while (!isSpaceChar(c));
			return res * sgn;
		}
		public int nI() {
			int c = read();
			while (isSpaceChar(c))
				c = read();
			int sgn = 1;
			if (c == '-') {
				sgn = -1;
				c = read();
			}
			int res = 0;
			do {
				if (c < '0' || c > '9')
					throw new InputMismatchException();
				res *= 10;
				res += c - '0';
				c = read();
			} while (!isSpaceChar(c));
			return res * sgn;
		}
		public int[] NIA(int n) //nextINtArray
		{
			int[] arr = new int[n];
			for (int i = 0; i < n; i++) {
				arr[i] = nI();
			}
			return arr;
		}
		public int[] NIA1(int n) //nextINtArray
		{
			int[] arr = new int[n+1];
			for (int i = 1; i <=n; i++) {
				arr[i] = nI();
			}
			return arr;
		}
		
		public long[] NLA(int n) //nextLongArray
		{
			long[] arr = new long[n];
			for (int i = 0; i < n; i++) {
				arr[i] = nL();
			}
			return arr;
}
		public long[] NLA1(int n) //nextLongArray
		{
			long[] arr = new long[n+1];
			for (int i = 1; i <=n; i++) {
				arr[i] = nL();
			}
			return arr;
}
		private boolean isSpaceChar(int c) {
			return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
		}
		private boolean isEndOfLine(int c) {
			return c == '\n' || c == '\r' || c == -1;
		}
	}
static class DSU
{
    int a[],size[],c=1,m;
    HashMap<String,Integer> hm=new HashMap<String,Integer>();
    DSU(int n)
    {
        a=new int[n+1];
        m=n;
        size=new int[n+1];
        for(int i=1;i<=n;i++)
    {
        a[i]=i;
        size[i]=1;
    }
    }
    void add(String x,int i)
    {
        hm.put(x,i);
    }
    int find(int n)
    {
        while(a[n]!=n)
        {
            a[n]=a[a[n]];
        n=a[n];
    }
        return n;
    }
    int[] eval()
    {
       int y[]=new int[m+1];
       for(int i=1;i<=m;i++)
       y[find(i)]++;
       return y;
    }
    void union(int a1,int b)
    {
        int x=find(a1);
        int y=find(b);
        if(size[x]>size[y])
    {
        a[y]=x;
        size[x]+=size[y];
    }
    else
    {
       a[x]=y;
       size[y]+=size[x];
    }
}
        //System.out.println(Arrays.toString(a));
}
class Segment
{
    int sum[];
    void build(int a[],int v,int l,int r)
    {
        if(l==r)
        sum[v]=a[l];
        else
        {
            int m=(l+r)/2;
            build(a,v*2,l,m);
            build(a,2*v+1,m+1,r);
            sum[v]=sum[v*2]+sum[2*v+1];
        }
    }
    void update(int a[],int l,int r,int x,int v,int y)
    {
        if(l==r&&r==y)
            sum[v]+=x;
        else if(l>y||y>r)
        return;
        else
        {
            int m=(l+r)/2;
            update(a,l,m,x,2*v,y);
            update(a,m+1,r,x,2*v+1,y);
            sum[v]=sum[2*v]+sum[2*v+1];
        }
    }
    int query(int v,int l,int r,int x,int y)
    {
        if(x>r||y<l)
        return 0;
        else if(x<=l&&r<=y)
        return sum[v];
        else
        {
            int m=(l+r)/2;
        return query(2*v,l,m,x,y)+query(2*v+1,m+1,r,x,y);  
    }
}
}

static class Trie
  {
      Trie child[]=new Trie[26];
      int count=0;
    }
   /* void insert(String a)
    {
        Trie tmp=root;
        for(int i=0;i<a.length();i++)
        {
            int v=a.charAt(i)-'a';
            if(tmp.child[v]==null)
            {
                tmp.child[v]=new Trie();
                
            }
                tmp=tmp.child[v];
            }
            if(tmp.count==0)
            r++;
            tmp.count=1;
        }*/
    }
    class Pairs implements Comparable<Pairs>
    {
        int x,y;String z;
        Pairs(int a,int b)
        {
            x=a;y=b;
        }
        @Override
         public int compareTo(Pairs a)
            {
            
            if(a.x>this.x||(a.x==this.x&&a.y<this.y)||(a.x==this.x&&a.y==this.y&&(a.z).equals("BhayanakMaut")))
            return 1;
            else
            return -1;
        }
    }