#include<stdio.h>
struct Rectangle{
    float length;
    float width;
};
void CalculateArea(struct Rectangle *r){
    r->area=r->length*r->width;
}
int main(){
    struct Rectangle rt;
    scanf("%d",&rt.length,&rt.width);
    if(rt.length<=0&&rt.width<=0){
        printf("Invalid input");
        return 0;
    }
    CalculateArea(&rt);
    printf("%d",rt.area);
    return 0;
    }