D - Strange Lunchbox

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

#define flush                    cin.ignore(numeric_limits<streamsize>::max(),'\n')
#define FASTERIO                 ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0)
#define NL                       cout<<'\n';
#define pi                       acos(-1.0) //3.1415926535897932384626
#define pb                       push_back
#define mk                       make_pair
#define mx                       100005
#define EPS                      1e-10
#define dpoint(x)                fixed<<setprecision(x)
typedef long long int            ll;
typedef double                   dl;
typedef unsigned long long int   ull;

//Funtions
template <class T> T digitsum(T n) {T sum = 0; while (n != 0) {sum += n % 10; n /= 10;} return sum;}
int gcd(int a, int b) { int x ; return x = __gcd(a, b);}
int lcm(int a, int b) {int y; return y = ((a) * ((b) / gcd(a, b)));}

// Debugger
#define gobug                   0
#define debugNS(a,b,c)          cout<<a<<b<<c<<endl;
#define debugN(b)               cout<<b<<endl;

bool cmp(pair<int, int>a, pair<int, int>b) {
    if(a<b)return true;
    return false;
}


int main() {


    FASTERIO; //cmt when use scanf & printf ;


   int tt, n; cin>>tt;
   int x,y; cin>>x>>y;
   n = tt;
   vector<pair<int,int>>mp;
   while(tt--){
        int a,b; cin>>a>>b;
        mp.pb({a,b});
   }


   for(int i=0; i<n; i++){
    for(int j=i+1; j<n; j++){
        if(cmp(mp[i],mp[j]))swap(mp[i],mp[j]);
    }
   }


    bool flg = false;
    int boll=0, ric=0, cnt=0;
    for(auto it:mp){
        boll+=it.first;
        ric+=it.second;
        cnt++;
        if(boll >= x && ric>=y){
            flg = true; break;
        }
    }
    if(flg)cout<<cnt<<endl;
    else cout<<-1<<endl;



    return 0;
}