#define MAXN 1000000
#include<iostream>
using namespace std;
bool isprime[MAXN+1];
void create(){
    memset(isprime,true,sizeof(isprime));
    isprime[0]=isprime[1]=false;
    for (int i=2;i*i<=MAXN;++i)
        for (int j=i*2;j<=MAXN;j+=i)
            isprime[j]=false;
}
double Triviality(int n){
    double sum;
    for (int i=1;i*2<=n;++i)
        if (n%i==0) sum+=(double)i;
    sum/=(double)n;
    return sum;
}
int main(void){
    create();
    int l,r;cin>>l>>r;
    if (l==1){
        cout<<"1"<<endl;
        return 0;
    }
    for (int i=l;i<=r;++i)
        if (isprime[i]){
           cout<<i<<endl;
           return 0;
        }
    double minimum=Triviality(l);
    int j=l;
    for (int i=l+1;i<=r;++i)
        if (minimum>Triviality(i)){
           j=i;
           minimum=Triviality(i);
        }
    cout<<j<<endl;
    return 0;
}

I request everyone not to help you until you stop posting programs in forum!