UVa 406

#include<bits/stdc++.h>
using namespace std;

bool chk[1009];
int total[1009];
vector< int > prime;

void seive()
{
    memset(chk,0,sizeof(chk));
    chk[0]=1;
    chk[1]=0;
    prime.push_back(1);
    for(int i=2;i<=1000;i++){
        if(chk[i]){
            continue;
        }
        prime.push_back(i);
        for(int j=2;i*j<=1000;j++){
            chk[i*j]=1;
        }
    }
    int cnt=0;
    for(int i=1;i<=1000;i++){
        if(chk[i]==0){
            cnt++;
        }
        total[i]=cnt;
    }
}

int main()
{
    seive();
    int n,c,i,j;
    while(cin>>n>>c){
        cout<<n<<" "<<c<<":";
        int sum = total[n];
        int x = sum/2;
        if(sum%2==0){
            i = x-c;
            j = x-1+c;
        }
        else{
            i = x-c+1;
            j= x-1+c;
        }
        if(i<0) i=0;
        if(j>=sum) j=sum-1;
        for(int z=i;z<=j;z++){
            cout<<" "<<prime[z];
        }
        cout<<"\n\n";
    }
    return 0;
}