#include<bits/stdc++.h>
#include<cstdio>
using namespace std;
 
#define REP(a,b,c) for(a=b;a<c;a++)
#define rep(x,y,z) for(x=y:x=z;x--)
#define PI 3.14159265359
 
int main(){
	int a,b;
	scanf("%d%d",&a,&b);
	for(int i=a;i<=b;i++){
		if(i%3==0) cout<<i<<endl;;
	}
}