An $n$-character string consisting of a block of \textbf{T} characters followed by a block of \textbf{F} characters. Find the index of the last \textbf{T} or print $-1$ if one dosen't exists. Indexation in the string starts from $0$. \InputFile One line of characters of length no more than $10^6$ characters. \OutputFile Print the index of the last \textbf{T} character. Or print $-1$ if \textbf{T} character dosen't exists.