#include <iostream>

using namespace std;

int main()
{
 int n;
 cin >> n; // Number of knights

 if(n==1) {
    cin >> n;
	cout << '0';
	return 0;
 }
 else if(n == 2) {
  int a, b;
  cin >> a >> b;
  cout << min(a, b);
  return 0;
 }
 else if( n == 3) {
    int a, b, c;
	cin >> a >> b >> c;
	cout << min(a, min(b, c));
	return 0;
 }

 int a[n + 1];
 for(int i = 0; i < n; i++)
 cin >> a[i];
 a[n] = a[0];
 int ans[n+1];
 ans[n-1] = a[n - 1];
 ans[n - 2 ] = a[n - 2] + a[0];

 for(int i = n - 3; i >= 0; i--)
 {
    ans[i] = a[i] + min(ans[i+1], ans[i+2]);
 }

 cout << min(ans[0], ans[1]);
}