n = int(input())
a = input()
z = 1
c = 0
y = 0
if a[-1] == '0':
    print('-1')
    exit()
for i in a:
    if i == '1':
        if y == 0:
            print(z,end=' ')
        else:
            print(c,end=' ')
            y = 0
            z -= 1
    else:
        if y == 0:
            c = z
            z += 1
            print(z,end=' ')
            y = 1
        else:
            print(z,end=' ')
    z += 1