            #include <stdio.h>
             
            int main()
            {long int a; long double b,c;
            scanf("%ld %llf %llf",&a,&b,&c);
            b=100*b+c;
            a=a*(long int)b;
            a=(a-a%100)/100;
            printf("%ld",a);
                return 0;
            }