#include<stdio.h>
#include<string.h>
typedef struct node
{
    char name,str[28],color;
}node;
int d[26],q[100],top,front;
void enq(int n)
{
    top=(top+1)%100;
    q[(top-1)%100]=n;
}
int exq(void)
{
    if((front+1)%100==top)return -1;
    front=(front+1)%100;
    return q[(front)%100];
}
int main(void)
{
    int n,i,j,max;
    node a[26];
    while(scanf("%d",&n)!=EOF&&n!=0)
    {
        for(i=0;i<n;i++)
        {
            scanf("%s",a[i].str);
            a[i].color='w';
        }
        front=0;top=1;
        a[0].color='g';
        d[0]=1;
        enq(0);
        j=exq();
        while(j!=-1)
        {
            for(i=2;i<strlen(a[j].str);i++)
            {
                if(a[a[j].str[i]-'A'].color=='w')
                {
                    d[a[j].str[i]-'A']=1;
                    a[a[j].str[i]-'A'].color='g';
                }
                if(a[a[j].str[i]-'A'].color=='g'&&d[a[j].str[i]-'A']==d[j])
                {
                    d[a[j].str[i]-'A']++;
                    enq(a[j].str[i]-'A');
                }
            }
            a[j].color='b';
            j=exq();
        }
        for(i=0,max=0;i<n;i++)
        if(d[i]>max)max=d[i];
        if(max==1)
        printf("%d channel needed.\n",max);
        else printf("%d channels needed.\n",max);
    }
    return 0;
}