#include <iostream>
#include <string>
#include <stdio.h>
using namespace std;

int main(void) {
    
    char str[10010];
    char str2[10010];//    string str2;
    int step, fullLenght=0;

    int delka;

    int g;
    int i = 0;
    
    
    do {
        scanf("%d\n", &step);
     
        if(step==0) break;

        i = 0;
        g = getchar();
	while (g != '\n') { 
            if(g == ' ') {
                g = getchar();
                continue;
            }
            
            if(g>= 'a' &&  g<= 'z') {
                g-=32;
            }
		str[i++] = g;
            g = getchar();
	}
        
        fullLenght = delka = i;
        int indexAkt=0;
//        int nazacatku=0;
//        while(true){
//            int i=nazacatku++;
//            for (i; i < fullLenght; i+=(step)) {
//                 str2[i]=str[indexAkt++];
//            }
//
//        
//        }
        int i, j;
        for (i = 0; i < step; i++) {
            j = i;
            for (j; j < fullLenght; j+=(step)) {
                //if (j+step < fullLenght) {
                    str2[j] = str[indexAkt++];
                //}
            }
        }
	/*if (delka <= step) {
		for(i=0; i<fullLenght;i++ )    {
            
        	    //pis = str[i];
	            //if(pis == ' ') continue;
            
                    putchar(str[i]);
		}
		putchar('\n');
		continue;
	}

	//str2 = new char[fullLenght];
       
        for(int i=0; i<delka;i++ )    {
            
            pis = str[i];
           
            
            result = ((actIndex*step) + (actIndex/fullLenght))%fullLenght;
            str2[result]=pis;
            actIndex++;
        }*/
	str2[fullLenght] = '\0';
        
        cout << str2 << endl;
        
        //delete []str2;
    } while (1);
    
    return 0;
    
}