#include <stdio.h>
int main(int argc, char* argv[]){
	int count = 0;
	int condition = 0;
	for(int i = 2; i <= 20; i++){
		if(i == 2 || i == 3){
			count++;
			printf("%d: %d \n",count,i);
		}
		if(i % 2 == 0 || i % 3 == 0){
			condition = 0;
		}else{
			count ++;
			printf("%d: %d \n",count, i);
		}
	}
}