public class LuckyNames {
	public static boolean isPrime(int n){
		int to = n  / 2;
		for(int i=2; i<=to ;i++) 
			if( n % i == 0) return false;
		return true;		
	}
	public static int luckyAverage( String name){
		int len = name.trim().length();
		double factor = 100.0/ len;
		double luckyness = 0;
		for(int i = 0 ;i < len; i++){
			int c = (int) name.charAt(i);
			if( isPrime(c))
				luckyness += factor;
		}
		return (int) luckyness;
		
	}
	public static void main(String[] args){
		System.out.println("SISCO:" + luckyAverage("SISCO") + "% lucky");
		System.out.println("cake:" + luckyAverage("cake") + "% lucky");
		System.out.println("Summer:" + luckyAverage("Summer") + "% lucky");		
		System.out.println("Virus:" + luckyAverage("Virus") + "% lucky");
				
	}
}