#include <iostream>#include <algorithm>using namespace std;int time[1010],n;int solve(int time[],int n){ if(n == 1) return time[0]; if(n == 2) return time[1]; if(n == 3) return time[0] + time[1] + time[2]; if(2*time[1] < (time[0] + time[n-2])) return time[0] + 2*time[1] + time[n-1] + solve(time,n-2); else return 2*time[0] + time[n-1] + time[n-2] + solve(time,n-2);}void bridge(int time[],int n){ if(n == 1) { cout << time[0] << endl; return; } if(n == 2) { cout << time[0] << " " << time[1] << endl; return ; } if(n == 3) { cout << time[0] << " " << time[2] << endl; cout << time[0] << endl; cout << time[0] << " " << time[1] << endl; return; } if(2*time[1] < time[0] + time[n-2]) { cout << time[0] << " " << time[1] << endl; cout << time[0] << endl; cout << time[n-2] << " " << time[n-1] << endl; cout << time[1] << endl; } else { cout << time[0] << " " << time[n-1] << endl; cout << time[0] << endl; cout << time[0] << " " << time[n-2] << endl; cout << time[0] << endl; } bridge(time,n-2);}int main(){ int i,j,k; while( cin >> n ) { for(i=0;i<n;i++) cin >> time[i]; sort(time,time + n); cout << solve(time,n) << endl; bridge(time,n); } return 0;}
