100以内的素数

public class primenumber{    public static void main(String arg[]){        int a,b,c;        System.out.print("1 2 3 5 7");                  for(a=11;a<=100;a+=2){            c=0;            for(b=3;b<=7;b+=2)                if(a%b==0)c=1;            if(c==0)System.out.print(" "+a);        }    }}