poj 3507 Judging Olympia

#include <iostream>#include <algorithm>using namespace std;int grades[6];int main(){    int i, sum;    double avg;    while (cin >> grades[0] >> grades[1] >> grades[2] >> grades[3] >> grades[4] >> grades[5])    {          if (grades[0] == 0 && grades[1] == 0 && grades[2] == 0 && grades[3] == 0 && grades[4] == 0 && grades[5] == 0)  break;          sum = 0;          sort(grades, grades+6);          for (i = 1; i < 5; i++)   sum += grades[i];          avg = sum * 1.0 / 4 * 1.0;          cout << avg << endl;    }   return 0;}