#include <stdio.h>

int main () {
  int n = 0;
  int s[10000] = {};
  
  int res = 0;
  
  int cnt = 0;
  
  res = scanf("%d", &n);
  for (int i = 0; i < n; i++) {
    res = scanf("%d", s+i);
    for (int j = 0; j < i; j++) {
      if (s[j] > s[i]) {
        cnt++;
      }
    }
  }
  
  if (cnt%2 == 1) {
    printf("-");
  }
  
  printf("1\n");
  
  return 0;
}