# include<iostream>

# include<cstdio>

# include<cstring>

# include<algorithm>

using namespace std;

int n,k,cnt,path[1000];

void dfs(int cur)

{

    if(cur>81)

        return ;

    if(cnt++==n){

        for(int i=0;i<cur;++i){

            printf("%c",char(path[i]+'A'));

            if(i%4==3&&i!=cur-1){

                if(i%64==63)

                    printf("\n");

                else

                    printf(" ");

            }

        }

        printf("\n%d\n",cur);

        return ;

    }

    for(int i=0;i<k;++i){

        path[cur]=i;

        int flag=1;

        for(int j=1;j*2<=cur+1;++j){

            int ok=1;

            for(int l=0;l<j;++l)

                if(path[cur-l]!=path[cur-l-j]){

                    ok=0;

                    break;

                }

            if(ok){

                flag=0;

                break;

            }

        }

        if(flag)

            dfs(cur+1);

        if(cnt>n)

            return ;

    }

}

int main()

{

    while(scanf("%d%d",&n,&k)&&(n+k))

    {

        cnt=0;

        dfs(0);

    }

    return 0;

}