import "dart:io";
import 'dart:async';
import 'dart:convert';
import 'dart:math' as Math;

void main() async {
  int N = int.parse(stdin.readLineSync());
  var lines = stdin.transform(utf8.decoder).transform(LineSplitter());
  List<int> A = [];
  await for(var line in lines) {
   A = line.split(' ').map((x) => int.parse(x)).toList();
  }
  for (int i=0; i<N;i++) {
  	if (A[i]==0) {
    	print(0);
        return;
    }
  }
  final M = Math.pow(10, 18);
  int r = 1;
  for (int i=0; i<N;i++) {
    r*=A[i];
    if (r > M) {
     	print(-1);
      	return;
    }
  }
  print(r);
}