func main()
	var n: int :: cui@inputInt()
	var k: int :: cui@inputInt()
	var a: []int :: #[n]int
	for i(0, n - 1)
		do a[i] :: cui@inputInt()
	end for
	
	var rnd: lib@Rnd :: lib@makeRnd(lib@sysTime() $ bit32)
	var ans: int :: 0
	var use: []bool :: #[n]bool
	for(1, 4)
		var map: dict<int, bool> :: #dict<int, bool>
		var mod: int :: rnd.rnd(2 ^ 50, 2 ^ 51)
		for ii(0, 2 ^ n - 1)
			var id: int :: ii
			var cnt: int :: 0
			for i(0, n - 1)
				do use[i] :: (id % 2 = 1)
				if(use[i])
					do cnt :+ 1
				end if
				do id :/ 2
			end for
			if(cnt >= k)
				var mul: int :: 1
				for i(0, n - 1)
					if(use[i])
						do mul :* a[i]
						do mul :% mod
					end if
				end for
				do map.add(mul, true)
				
				var sum: int :: 0
				for i(0, n - 1)
					if(use[i])
						do sum :+ a[i]
					end if
				end for
				do map.add(sum, true)
			end if
		end for
		do ans :: [ans, ^map].max()
	end for
	do cui@print("\{ans}\n")
end func