#include<fstream.h>
int main()
{int np,n,f,i,v[5000],j,a,b;
ifstream q("densitate.in");
ofstream w("densitate.out");
q>>n>>f;
v[1]=0;
v[0]=0;
for(i=2;i<=n;i++)
 v[i]=1;
i=2;
while(i<n/2)
	{for(j=2;j<=n/i;j++)
		v[i*j]=0;
	i++;
	while(v[i]==0)
		i++;}
np=0;
for(i=2;i<=n;i++)
	{if(v[i]==1)
	 np++;
   v[i]=np;}
for(i=1;i<=f;i++)
	{q>>a>>b;
	w<<v[a]-v[b]<<"\n";}
return 0;}