while 1:
n, m = map(int, input().split())
if n == 0:
break
l = [*map(int, input().split())]
ans = 0
for i in range(n):
for j in range(i + 1, n):
s = l[i] + l[j]
if s > m:
continue
ans = max(ans, l[i] + l[j])
print(ans if ans > 0 else "NONE")