#include<bits/stdc++.h>
using namespace std;
#define fast {ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);}
typedef long long int ll;
typedef string S;
#define M 1e18
#define AS 250005
#define sp cout<<' '
#define nw cout<<endl
#define rt return
#define __ template<typename T, typename... Types>
void in() {rt;} __ void in(T &a, Types&... b){cin>>(a); in(b...);}
void o() {rt;}  __ void o(T a, Types... b){cout<<(a);sp; o(b...);}
#define fr(Hi,a,n) for(ll Hi=a;Hi<=n;Hi++)
#define frm(Hi,a,n) for(ll Hi=n;Hi>=a;Hi--)
#define P pair<ll,ll>
#define vc vector<ll>
#define pb push_back
#define MP map<ll,ll>
bool sortin(const pair<ll,ll> &e,const pair<ll,ll> &f){return (e.first<f.first);}
bool POT(ll x){return x && (!(x&(x-1)));}
ll i,j,k,l,m,n,p,q,r,a,b,c,x,y,z,ts,mn=1e18,mod=1e9+7;
ll ar[AS],br[AS],xr[AS],tem[AS];

int main()
{
    fast;
    in(n,a,b);
    fr(i,0,n-1)
    {
        in(x,y);
        if(x<a and y>b)c=1;
    }
    if(c)o("Yes");
    else o("No");
}


#include <bits/stdc++.h>
using namespace std;
 
int main() {
  int n,k,m,sum,z;
  sum=0;
  cin >> n >> k >> m;
  vector<int> A(n-1);
  for (int i=0;i<n-1;i++)cin >> A.at(i);
  
  for (int j=0;j<n-1;j++)sum+=A.at(j);
  
  if(sum+k<n*m)cout << "-1" <<endl;
  else{
    z=n*m-sum;
    if(z<=0)cout << 0 <<endl;
    else cout << z <<endl;
  }
} 