// C - Collinearity
#include <bits/stdc++.h>
using namespace std;
using vi = vector<int>;
using ll = long long;
#define rp(i,s,e) for(int i=(int)(s);i<(int)(e);++i)

int main(){
	int n; cin>>n;
	vi X, Y;
	rp(i, 0, n){
		int x, y; cin>>x>>y;
		X.push_back(x);
		Y.push_back(y);
	}
	rp(a, 0, n-1) rp(b, a+1, n) rp(c, 0, n){
		if(c == a || c == b) continue;
		int dx = X[b] - X[a];
		int dy = Y[b] - Y[a];
		ll dx_y = dx*Y[c];
		ll dx_fx = dy*(X[c] - X[a]) + dx*Y[a];
		if(dx_y == dx_fx){
			puts("Yes");
			return 0;
		}
	}
	puts("No");
}

#include <bits/stdc++.h>
#define rep(i,n) for(ll i=0;i<(n);++i)
#define all(a) (a).begin(),(a).end()
#define dunk(a) cout << (a) << endl
#define rall(a) (a).rbegin(),(a).rend()
const int INF = 2e9;
using namespace std;
using Graph = vector<vector<int>>;
typedef pair<int,int> P;
typedef long long ll;

int main(){
    int n, k, m; cin >> n >> k >> m;
    int sum = 0;
    vector<int> a(n); 
    rep(i,n-1){
        cin >> a[i];
        sum+= a[i];
    }

    if(n*m < sum) dunk(0);
    else if(n*m > sum + k) dunk(-1);
    else dunk(n*m-sum);
}

    
