Using the sieve method is sufficient.
The answer is very large, remember that lld and regular records may not be fast enough.
Utilize the cumulative property to record and print the answer.
//====================================================================||
// ||
// ||
// Author : GCA ||
// 6AE7EE02212D47DAD26C32C0FE829006 ||
//====================================================================||
#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
#include <cmath>
#include <climits>
#include <vector>
#include <set>
#include <map>
#include <queue>
#include <cctype>
#include <utility>
using namespace std;
#ifdef ONLINE\_JUDGE
#define ll "%lld"
#else
#define ll "%I64d"
#endif
typedef unsigned int uint;
typedef long long int Int;
#define Set(a,s) memset(a,s,sizeof(a))
#define Write(w) freopen(w,"w",stdout)
#define Read(r) freopen(r,"r",stdin)
#define Pln() printf("\\n")
#define I\_de(x,n)for(int i=0;i<n;i++)printf("%d ",x\[i\]);Pln()
#define De(x)printf(#x"%d\\n",x)
#define For(i,x)for(int i=0;i<x;i++)
#define CON(x,y) x##y
#define Pmz(dp,nx,ny)for(int hty=0;hty<ny;hty++){for(int htx=0;htx<nx;htx++){\\
printf("%d ",dp\[htx\]\[hty\]);}Pln();}
#define M 2000006
#define PII pair<int,int\>
#define PB push\_back
#define oo INT\_MAX
#define Set\_oo 0x3f
#define Is\_debug true
#define debug(...) if(Is\_debug)printf("DEBUG: "),printf(\_\_VA\_ARGS\_\_)
#define FOR(it,c) for(\_\_typeof((c).begin()) it=(c).begin();it!=(c).end();it++)
#define eps 1e-6
bool xdy(double x,double y){return x>y+eps;}
bool xddy(double x,double y){return x>y-eps;}
bool xcy(double x,double y){return x<y-eps;}
bool xcdy(double x,double y){return x<y+eps;}
int min3(int x,int y,int z){
int tmp=min(x,y);
return min(tmp,z);
}
int max3(int x,int y,int z){
int tmp=max(x,y);
return max(tmp,z);
}
Int phi\[M\];
Int dphi\[M\];
Int dp\[M\];
void pre(){
Set(phi,0);
phi\[1\]=1;
for(int i=2;i<M;i++){
if(!phi\[i\]){
for(int j=i;j<M;j+=i){
if(!phi\[j\])phi\[j\]=j;
phi\[j\]=phi\[j\]\*(i-1)/i;
}
}
}
// for(int i=2;i<M;i++)printf("%d\\n",phi\[i\]);
Set(dphi,0);
for(int i=2;i<M;i++){
for(int j=i;j!=1;j=phi\[j\])dphi\[i\]++;
}
Set(dp,0);
for(int i=2;i<M;i++){
dp\[i\]=dp\[i-1\]+dphi\[i\];
}
}
int main() {
ios\_base::sync\_with\_stdio(0);
int test;
pre();
scanf("%d",&test);
while(test--){
int x,y;
scanf("%d%d",&x,&y);
printf("%lld\\n",dp\[y\]-dp\[x-1\]);
}
}