modificare

Task

You are given a string $s$ which contains only small lowercase letters. Find the minimum number of operations required such that $s$ will have the string roalgo as a substring. The operation we are allowed to use is to replace one of the letters with another.

Input data

The first line will contain the given string $s$.

Output data

The first line will contain an integer $x$, the number of operations required to get the string roalgo as a substring. If the substring is already present, print $0$.

Constraints and clarifications

• $6 \leq |s| \leq 100 \ 000$, where $|s|$ is the length of $s$.

Example

stdin

qaorxqlgp

stdout

3

Explanations

The minimal number of operations is $3$ (substring rxqlgp can be transformed to roalgo by replacing x, q and p with the suitable letters.