1 #include<stdio.h>
 2 #include<string.h>
 3 const int MAXN= 3000010;
 4 __int64 dp[MAXN];
 5 int main(){
 6     memset(dp,0,sizeof(dp));
 7     dp[1]=1;
 8     for(int i=2;i<MAXN;i++){
 9         if(dp[i])continue;
10         for(int j=i;j<MAXN;j+=i){
11             if(!dp[j])dp[j]=j;
12             dp[j]=dp[j]/i*(i-1);
13         }
14     }
15     for(int i=2;i<MAXN;i++)dp[i]+=dp[i-1];
16     int a,b;
17     while(~scanf("%d%d",&a,&b))printf("%I64d\n",dp[b]-dp[a-1]);
18         return 0;
19 }