var used: []bool
var k: []int
func main()
	var n: []char :: cui@input()
	do @k :: #[^n]int
	for i(0, ^n - 1)
		do @k[i] :: n[i] $ int - '0' $ int
	end for
	do @used :: #[^n]bool
	var ans: int :: f()
	do cui@print("\{ans}\n")
	
	func f(): int
		var res: int :: 0
		for i(0, ^@k - 1)
			if(@used[i])
				skip i
			end if
			if(@k[i] = 0)
				skip i
			end if
			for j(i + 1, ^@k - 1)
				if(@used[j])
					skip j
				end if
				for k(j + 1, ^@k - 1)
					if(@used[k])
						skip k
					end if
					var a: int :: @k[i]
					var b: int :: @k[j]
					var c: int :: @k[k]
					if(a <> b & b = c)
						do @used[i] :: true
						do @used[j] :: true
						do @used[k] :: true
						do res :: [res, f() + a * 100 + b * 11].max()
						do @used[i] :: false
						do @used[j] :: false
						do @used[k] :: false
					end if
				end for
			end for
		end for
		ret res
	end func
end func