#include <stdio.h>
#include <math.h>

int main(void) {
	long long int n, l;
	long long int d_max;
	long long int i, j;
	int flag;
	long long int count = 0;
	int prime[10000] = {0};
	scanf("%lld%lld", &n, &l);
	d_max = l / (n - 1);

	if(d_max >= 2){
		count += l - 2 * (n - 1) + 1;
	}
	for(i = 3;i <= d_max;i += 2){
		flag = 1;
		for(j = 2;j <= sqrt(i);j++){
			if(i % j == 0){
				flag = 0;
				break;
			}
		}
		if(flag == 1){
			//printf("%d is prime.\n", i);
			count += l - i * (n - 1) + 1;
		}
	}
	printf("%lld\n", count);
		
	return 0;
}