S

file = open('input.txt')
stack = []
s = ''

for line in file:
    line = line.strip()

    if '+' in line:
        if line[1:] not in stack:
            stack.append(line[1:])
        else:
            s = 'ERROR'
            break

    elif '#' in line:
        if line[1:] not in stack:
            stack.insert(0, line[1:])
        else:
            s = 'ERROR'
            break

    elif line == '^':
        if len(stack) != 0:
            stack.pop(-1)
        else:
            s = 'ERROR'
            break

    elif line == '/':
        if len(stack) != 0:
            stack.pop(0)
        else:
            s = 'ERROR'
            break
    #print(stack)

file.close()

if s != 'ERROR' and len(stack) == 0:
    s = 'EMPTY'
if s != 'ERROR' and s != 'EMPTY':
    stack.reverse()
    s = ' '.join(stack)

file = open('output.txt', 'w')
file.write(s)
file.close()