import sys
import time
f1=open('in.txt','r')
f2=open('out.txt','w')
a=[]
for i in range(0,6):
        a.append(f1.readline().split(" "))
print a
mark=[0]*len(a)
mark[4]=1
stack=[]
stack.append(4)
r=len(a)
c=len(a)
i=4
j=0
x=0
ans=[4]
while len(stack) != 0:
    for j in range(0,c):
            if ( len(stack)==0):
                break

            if (mark.count(1)== r):
                x=1                
                break
            
            if(mark[j]==1 ):
                continue
            if(int(a[i][j])==1):
                mark[j]=1
                stack.append(j)
                ans.append(j)
                i=j
                break
            if(j==r-1):
                stack.pop()
                print len(stack)
                i=stack[len(stack)-1]
                
                break
    if(x==1):
       break
res=''
for i in range (0, 6):
    if  ans[i]==0:
        res=res+"A "
    elif ans[i]==1:
        res=res+"B "
    elif ans[i]==2:
        res=res+"C "
    elif ans[i]==3:
        res=res+"D "
    elif ans[i]==4:
        res=res+"E "
    elif ans[i]==5:
        res=res+"F"
f2.write(res)
f1.close()
f2.close()