java :递归

public class BRRead {
   public static void main(String args[]) 
   {
        System.out.print(f(30));
   }

   public static int f(int x){

            if (x == 1 || x == 2) {
                
                return 1;
            }else{

                return f(x-1) + f(x-2);
            }
   }
}


f(x) = f(x-1)+f(x-2); x>=3;
f(1) = 1;
f(2) = 1;