#include <stdio.h>
int multi(int m, int n){
	if (n==1){
		return m;
	}
	
 else return m+multi(m,n-1);
 }

int main(void) {
 int m,n;
 scanf("%d",&m);
 scanf("%d",&n);
 int result = multi(m,n);
 printf("%d\n",result);
	// your code goes here
	return 0;
}