Use the sieve method.
Remember to use lld for large answers and regular records may not be fast enough.
Use 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\[x-1\]);
}
}