import java.util.Arrays;

/*        If we list all the natural numbers below 10 that are multiples of 3 or 5, we get 3, 5, 6 and 9.
          The sum of these multiples is 23.
          Find the sum of all the multiples of 3 or 5 below 1000.

          21 = 3 + 5 + 6 + 10
*/
class Ex1 {
    static void run(int x){
        int i = 0,tmp = 0,results = 0;
        while(true){
            i++;
            tmp = i*3;
            if(tmp>x)break;
            results+=tmp;
            tmp = i*5;
            if(tmp>x)continue;
            results += tmp;
        }
        System.out.println(results);


    }
}