#include<stdio.h>
#include<string.h>
int main()
{
    char s[1001];
    int numrow;
    scanf("%s",s);
    scanf("%d",&numrow);
    int len = strlen(s);
    if(numrow < 1)
    {
        printf("Invalid input");
        return 0;
    }
    if(numroe == 1 || numrow>= len)
    {
       printf("%s",s);
       return 0;
    }
    char row[numrow][1001];
    char rowlen[numrow];
    for(int i=0;i<numrow;i++)
    {
        rowlen[i]=0;
        row[i][0]='\0';
    }
    int currow=0;
    int goingdown=0;
    for(int i=0;i<len;i++)
    {
        int l=rowlen[currow];
        row[currow][1]=s[i];
        row[currow][+ 1]='\0';
        rowlen[currow]++;
        if(currow==0 || currow== numrow - 1)
        {
            goingdown=!goingdown;
            currow+= goingdown ? 1:-1;
        }
        for(int i=0;i<numrow;i++)
        printf("%s",row[i]);
    }
    return 0;
    
}