Untitled

def magic():
    q = []
    a = list(map(int, input().split()))
    a.sort(reverse=True)
    for j in a:
        if j % 5 == 0:
            q.append(j)
            break
    if len(q) == 0:
        print(-1)
    else:
        print(q[0])
        
n = int(input())
if n == 0:
    print(-1)
else:
    magic()