import std.stdio, std.conv, std.algorithm, std.range, std.array, std.string, std.uni, std.bigint, std.math;                                                                                                                                                                                  void main() {                                                                                    auto n = readln.chomp.to!uint;                                                                 auto an = readln.split.to!(int[]);                                                             auto sum = 0;                                                                                  auto cnt = 0;                                                                                  foreach (a; an) {                                                                                if (sum != 0 && (sum + a) * sum >= 0) {                                                          auto na = -sum - sgn(sum);                                                                     cnt += abs(na - a);                                                                            a = na;                                                                                      }_                                                                                             sum += a;                                                                                    }                                                                                              writeln(cnt);                                                                                } 