import kotlin.math.abs

fun main(args : Array<String>) {
	val T = (readLine() ?: "").run { toInt() }
	val xLst = IntRange(1, T).map { readLine() ?: "" }.map { it.toInt() }
	
	(listOf(0) + xLst)
		.zipWithNext()
		.all { abs(it.first - it.second) == 1 }
		.let {
			when(it) {
				true -> "T"
				false -> "F"
			}
		}
		.let { println(it) }
}