3259. Mysterious Number

Mysterious Number refers to a number which can be divisible by the number of distinct factors that it has. For instance, 1 (1 factor), 12 (6 factors) and 9 (3 factors) are Mysterious Numbers, but 7(2 factors) or 16 (5 factors) are not.

Given two integers low and high, please calculate the number of Mysterious Numbers between low and high, inclusive.

Input

For each test case, there are two integers low and high in one line separated by spaces. 1 ≤ low ≤ high ≤ 1,000,000

Output

Print out the number of Mysterious Numbers between low and high, inclusive.

Sample Input

1 10
10 15

Sample Output

4

1

#include<stdio.h>
#include<cstring>
const int num=1000001;
int a[num],b[num];
void f(){
	memset(a,0,sizeof(a));
	a[1]=1;
	for(int i=2;i<num;i++)
	{
		if(!a[i])
		{
			a[i]=2;
			for(int j=i+i;j<num;j=j+i)
			{
				a[j]=a[j]+1;
			}
		}
		else
		{
			a[i]=a[i]+2;
			for(int j=i+i;j<num;j=j+i)
				a[j]=a[j]+1;
		}
	}
	b[0]=0;
	for(int i=1;i<num;i++)
	{
		if(i%a[i]==0)
			b[i]=1;
		b[i]=b[i]+b[i-1];
	}
}
int main(){
	int low,high,r;
	f();
	while(scanf("%d%d",&low,&high)!=EOF){
		
		printf("%d\n",b[high]-b[low-1]);
	}	
	return 0;
}