#include<bits/stdc++.h> using namespace std; long a[103] ; int main(){ int n; cin >> n; for(int i = 1; i <= n; i++) cin >> a[i]; int x = a[2] - a[1]; for(int i = 4; i <= n; i++){ int y = a[i] - a[i-1]; if(x != y){ cout << "No" << endl; return 0; } } cout << "Arithmetic Sequence" << endl; return 0; }