Homework - Variable tab problem

package sitoeratostenesa;
public  class SitoEratostenesa1{ 
             SitoEratostenesa1 (int n){
               
       boolean sito [] = new boolean[n+1];{
    
    for(int i=2; i<Math.sqrt(n); i++) {  
        if(sito[i]==true)          
            continue;
         for(int k=2*i; k<n; k+=i){
             sito[k] = true;
           }
    }
    }
             }
public  boolean prime (int m){
            if (sito[m] == false){
               System.out.print(m+" "); return true;}else{
                                        
         System.out.print(m+" ");   return false;}
}

}