// inputに入力データ全体が入る
function Main(input) {
  input = input.trim().split('\n');
  var N = input[0];
  var As = input[1].split(' ').map(x=>BigInt(x));
  var prod = 1n
  if (As.indexOf(0n) != -1){
    prod = -1n
  }else{
    for (i=0;i<N;i++){
      prod *= As[i];
      if (prod > 10n ** 18n){
        prod = -1n;
        break;
      }
    }
  }
  console.log(prod.toString());
}

Main(require("fs").readFileSync("/dev/stdin","utf8"));
