#include <stdio.h>
int main()
{
	char a;
	int n;
	scanf("%d",&n);
	n=n%26;
	getchar();
	while(scanf("%c",&a)!='\n'&&a<='z'&&a>='a')
	{
		if(a<='z'-n)
		printf("%c",a+n);
		else
		printf("%c",a-26+n);
	}
	return 0;
}