A12589 | Catch Overflow!

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 $x$ .

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

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

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

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