1051B - Relatively Prime Pairs.cpp

#include<bits/stdc++.h>
#define endl '\n'
#define ll long long int
#define loop(i,a,b)           for(ll i=a;i<=b;++i)
#define pb                    push_back
#define F                     first
#define S                     second
#define mp                    make_pair
#define clr(x)                x.clear()
#define MOD                   1000000007
#define itoc(c)               ((char)(((int)'0')+c))
#define vl                    vector<ll>
#define SZ(x)                 (x).size()
#define all(p)                p.begin(),p.end()
#define mid(s,e)              (s+(e-s)/2)
#define sv()                  ll t,n; scanf("%lld",&t);n=t; while(t--)
#define tcase()               ll t,n; cin>>t;n=t; while(t--)
#define iscn(num)             scanf("%d",&num);
#define scn(num)              scanf("%lld",&num);
#define dbg(x)                cout <<"( "<<#x << " = " << x << " )"<<endl
using namespace std;
const ll INF = 2e18 + 99;
typedef pair<ll,ll> Pair;
typedef vector<ll> vec;;
void FAST_IO();
////////////////////////

int main()
{
	ll l, r; scanf("%lld%lld",&l,&r);
	ll need_pair=(r-l+1)/2;
	vector<Pair> v;
	ll curr_pair=0;
	for(ll i=l; i<r ; i+=2){
		if(curr_pair==need_pair)
			break ;
		v.emplace_back(make_pair(i,i+1));
		curr_pair++;
	}
	if(curr_pair==need_pair)
	{
		puts("YES");
		for(auto i : v)
			printf("%lld %lld\n",i.first, i.second);
	}else{
		puts("NO");
	}
    return 0;
}

void FAST_IO()
{
    // ios_base::sync_with_stdio(0);
    //cin.tie(NULL);
    //cout.tie(NULL);
    //cout.setf(ios::fixed);
    //cout.precision(2);

}