#include <bits/stdc++.h>

using namespace std;

int n, p[1001],i;

int verif(double d)
{
    set<double> nrdrepte;
    for (i=1;i<=n;i++)
        nrdrepte.insert(p[i]-d*i);
    return (nrdrepte.size()==2);
}

int main()
{
    cin>>n;
    for (i=1;i<=n;i++)
        cin>>p[i];
    if (verif(p[2]-p[1])||verif(p[3]-p[2])||verif((p[3]-p[1])*1.0/2))
        cout<<"Yes"<<endl;
    else cout<<"No"<<endl;
    return 0;
}