public class myzeta {
    static double myzeta(double s,int n) {
	double z;
	int k;
	z=0;
        for (k=1; k<n; k++) {
	    z=z+1/Math.pow(k,s);
        }
        return z;
    }
    public static void main(String[] args) {
	System.out.println(myzeta(3,10));
    }
}