#include <cstdio>
#include <cstdlib>

int main () {
char *resArr, in, inArr[10000];
int step, len, pos, inPos, cnt;

scanf ("%d", &step);

while (step!=0) {
len=0;
in=getc (stdin);

in=getc(stdin);
while (in!='\n') {
if (in!=' ') inArr[len++]=in;
in=getc(stdin);
}
resArr=new char [len+1];


inPos=0;
cnt=1;
for (pos=0; inPos<len;) {
inArr[inPos]>='a' ?  resArr[pos]=inArr[inPos++] - 32 : resArr[pos]=inArr[inPos++];
pos=(pos+step);
if (pos>=len) {pos=cnt++;}

}

resArr[len]='\0';

printf ("%s\n", resArr);


delete [] resArr;
scanf ("%d", &step);
}



return 0;
}