TF Problem

An $n$-character string consisting of a block of T characters followed by a block of F characters. Find the index of the last T or print $-1$ if one dosen't exists. Indexation in the string starts from $0$.

Input

One line of characters of length no more than $10^6$ characters.

Output

Print the index of the last T character. Or print $-1$ if T character dosen't exists.

Examples