#include <stdlib.h>
#include <stdio.h>

int main(int argc, char** argv) {
    
    unsigned step, len; //, spaces = 0;
    char cur, input[10001], output[10001];
    
    while (true) {
        len = 0;
        scanf("%u", &step);
        if (!step)
            break;
        getchar();
        /*getchar("%s", input);*/

        while ((cur = getchar()) != '\n') {
            if (cur == ' ')
                continue;
            if (cur >= 'a' && cur <= 'z')
                input[len] = cur+'A'-'a';
            else
                input[len] = cur;
            len++;
        }
        input[len] = 0;

        if (len > step) {
            unsigned pos = 0, round = 0;
            for (unsigned i = 0; i < len; i++) {
                if (pos >= len)
                    pos = ++round;
                output[pos] = input[i];
                pos += step;
            }
            output[pos] = 0;

            printf("%s\n", output);
        }
        else 
            printf("%s\n", input);
    }
    
    return (EXIT_SUCCESS);
}