uva10783

#include<stdio.h>
int main()
{
    int a,b,i,sum;
    while(scanf("%d%d", &a,&b)==2)
    {
        if(a%2==1 && b%2==1)
        {
            i=a+2;
            for(i=a+2;i<=b;i=i+2)
            {
                sum =a+i;
                a=sum;
            }
            printf("%d\n",sum);
        }
    }
    return 0;
}