#include <stdio.h>
#include <string.h>
int main()
{
int i,j,k,n,len;
char w[410];
freopen("in.txt","r",stdin);
freopen("out.txt","w",stdout);
while(1)
{
scanf("%d",&n);
if (n==0) break;
scanf("%s",w);
len=strlen(w);
for (i=0;i<n;i++)
{
j=i+1;
while(j<=len)
{
printf("%c",w[j-1]);
j=j+(n+n-i-i-1);
if (j>len) break;
printf("%c",w[j-1]);
j=j+i+i+1;
}
}
printf("\n");
}
return 0;
} |