#include<cstdio>

int i,j,a,b[20];

int main()
{
    freopen("prod.in","r",stdin);
    freopen("prod.out","w",stdout);

    for(i=1;i<10;++i)
    {
        scanf("%d",&a);
        while(a)
        {
            b[++b[0]]=i;
            --a;
        }
    }

    printf("%d\n",b[1]*b[2]);

    fclose(stdin);
    fclose(stdout);

    return 0;
}