Codeforces Problem-230A-Dragons

 #include <iostream>
#include <cstdio>
#include <cstring>
#include <map>
#include <string>
#include <vector>
#include <cmath>
#include <cctype>
#include <sstream>
#include <set>
#include <list>
#include <stack>
#include <queue>
#include <algorithm>
#define sf scanf
#define pf printf
#define sfint scanf ("%d %d",&a,&b)
#define sfl scanf ("%ld %ld",&a,&b)
#define sfll scanf ("%I64d %I64d",&a,&b)
#define sfd scanf ("%lf %lf",&a,&b)
#define sff scanf ("%f %f",&a,&b)
#define lp1(i,n) for(i=0;i<n;i++)
#define lp2(i,n) for(i=1;i<=n;i++)
#define LL long long
#define L long
#define mem(c,v) memset(c,v,sizeof(c))
#define ui unsigned int
#define ull unsigned long long int
#define nl puts("")
#define sq(x) ((x)*(x))
#define MX 1000005
#define N 100
#define MOD 10000000007
#define pb push_back
#define pi acos(-1.0)
#define sz size()
#define gc getchar ()
#define ps push
#define clr clear
#define inf 2147483647
#define bn begin()
#define ed end()

using namespace std;

struct my
{
    LL x;
    LL y;
};

bool cmp(my a, my b)
{
    return a.x < b.x;
}

int main()
{
    LL s,n,i;
    bool f = false;
    my ar[10009];

    while(cin >> s >> n)
    {
        LL t=s;

        for(i=0;i<n;i++)
        {
            cin >> ar[i].x >> ar[i].y;
        }

        sort(ar,ar+n,cmp);

    //        for(i=0;i<n;i++)
    //        {
    //            cout << ar[i].x << " " << ar[i].y << endl;
    //        }

        for(i=0;i<n;i++)
        {
            if(t > ar[i].x)
            {
                t+=ar[i].y;
            }

            else
            {
                f=true;
                break;
            }
        }

        if(f) cout << "NO\n";
        else cout << "YES\n";

        f=false;
    }

    return 0;
}