FUN max(a, b) = IF a > b THEN a ELSE b FI

-- n anzahl schleifendurchlaeufe
-- m bisheriges maximum
FUN LOOP(n, m) = IF n > 0 THEN
		 LET
			x = READ()
		 IN
			LOOP(n - 1, max(m, x))
		 ELSE
			m
		 FI

FUN abs(n) = IF n > 0 THEN n ELSE -n FI

FUN main() = 
	LET a = READ()
--	    b = READ()
	IN
	    --WRITE(max(a, b))
	    WRITE(LOOP(abs(a), -47110815))