#include <stdio.h>

int main(void)
{int m,n,X,total;

printf("数値を入力してください");
scanf("%d",&m);
printf("今入力した数値以上の数値を入力してください");
scanf("%d",&n);

total = 0;
X = 0;
if(m%3 == 0)
{total = total + m;
{while(m<=n)
m = m + 3;}
printf("%d",total);}
else if(m%3 == 2)
{while(m<=n)
{total = total + X;
X = m + 1;
m = m + 3;}
printf("%d",total);}
else
{while(m<=n)
{total = total + X;
X = m + 2;
m = m + 3;}
printf("%d",total);}
}