#include <bits/stdc++.h>   using namespace std;   template <class T>   void checkmax(T &t, T x) {     if (x > t) t = x;   }   template <class T>   void checkmin(T &t, T x) {     if (x < t) t = x;   }   template <class T>   void _checkmax(T &t, T x) {     if (t == -1 || x > t) t = x;   }   template <class T>   void _checkmin(T &t, T x) {     if (t == -1 || x < t) t = x;   }   int main() {     int n, num, flag;     double dou, sum, sub;     while (cin >> n) {       sum = num = flag = 0;       for (int i = 0; i < (2 * n); ++i) {         scanf( %lf , &dou);         sub = ceil(dou) - dou;         sum += sub;         if (sub < 10e-4 && sub > -10e-4) num++;       }       sum -= n - num;       if (num == 0)         printf( %.3lf n , fabs(sum));       else {         for (int i = 0; i < (num); ++i) {           if (fabs(sum) > fabs(sum - 1))             sum = sum - 1;           else {             printf( %.3lf n , fabs(sum));             flag = 1;             break;           }         }         if (!flag) printf( %.3lf n , fabs(sum));       }     }     return 0;   }   