#include<stdio.h>
int main()
{
    int n,m;
    scanf("%d %d",&n,&m);
    if(n==1&&m==1)
        printf("1");
    else if(n%2==0 &&m%2==0)
    {
        printf("%d",n+m-2);

    }
    else if(n%2==0 &&m%2!=0)
    {
        printf("%d",n+m-2);

    }
    else if(m%2!=0 &&n%2==0)
    {
        printf("%d",n+m-2);

    }
    else if(m%2!=0 &&n%2!=0)
    {
        printf("%d",n+m-2);

    }


}