main :: IO ()
main = interact $ f . g . h . map read . tail . words

h :: [Int] -> [Int]
h [x] = if x == -1 || x == 1 then [] else [10, 20]
h ys  = ys

g :: [Int] -> [Int]
g [x] = []
g (x:y:ys) = (abs (x - y)) : g (y:ys)

f :: [Int] -> String
f xs = if a == 0 then "T" else "F"
    where
        a = length $ filter (/= 1) xs