import java.util.*; 
 
public class Main{
    public static void main(String[] args){
	    Scanner sc=new Scanner(System.in);
            int N =sc.nextInt();
  		    long[] A = new long[N];
  		    long ans=1;
		    for(int i=0; i<N; i++){
    		    A[i]=sc.nextLong();
          	    if(A[i]==0){
            	    ans=0;
                }
    	    }
  	    	if(ans!=0){
		    	for(int i=0; i<N; i++){
            	if(A[i] <= (long)Math.pow(10,18)/ans){
                	ans *= A[i];
            	}else{
          	    	ans=-1;
                	break;
            	}
    		}
  	    }
    	System.out.println(ans);
    }
} import java.util.*; util.* java public class Main{
    public static void main(String[] args){
	    Scanner sc=new Scanner(System.in);
            int N =sc.nextInt();
  		    long[] A = new long[N];
  		    long ans=1;
		    for(int i=0; i<N; i++){
    		    A[i]=sc.nextLong();
          	    if(A[i]==0){
            	    ans=0;
                }
    	    }
  	    	if(ans!=0){
		    	for(int i=0; i<N; i++){
            	if(A[i] <= (long)Math.pow(10,18)/ans){
                	ans *= A[i];
            	}else{
          	    	ans=-1;
                	break;
            	}
    		}
  	    }
    	System.out.println(ans);
    }
} Main public static void main(String[] args){
	    Scanner sc=new Scanner(System.in);
            int N =sc.nextInt();
  		    long[] A = new long[N];
  		    long ans=1;
		    for(int i=0; i<N; i++){
    		    A[i]=sc.nextLong();
          	    if(A[i]==0){
            	    ans=0;
                }
    	    }
  	    	if(ans!=0){
		    	for(int i=0; i<N; i++){
            	if(A[i] <= (long)Math.pow(10,18)/ans){
                	ans *= A[i];
            	}else{
          	    	ans=-1;
                	break;
            	}
    		}
  	    }
    	System.out.println(ans);
    } main {
	    Scanner sc=new Scanner(System.in);
            int N =sc.nextInt();
  		    long[] A = new long[N];
  		    long ans=1;
		    for(int i=0; i<N; i++){
    		    A[i]=sc.nextLong();
          	    if(A[i]==0){
            	    ans=0;
                }
    	    }
  	    	if(ans!=0){
		    	for(int i=0; i<N; i++){
            	if(A[i] <= (long)Math.pow(10,18)/ans){
                	ans *= A[i];
            	}else{
          	    	ans=-1;
                	break;
            	}
    		}
  	    }
    	System.out.println(ans);
    } Scanner sc=new Scanner(System.in); sc new Scanner(System.in) int N =sc.nextInt(); N sc.nextInt() sc.nextInt sc long[] A = new long[N]; A new long[N] N long ans=1; ans 1 for(int i=0; i<N; i++){
    		    A[i]=sc.nextLong();
          	    if(A[i]==0){
            	    ans=0;
                }
    	    } int i=0; int i=0; i 0 i<N i N i++ i++ i {
    		    A[i]=sc.nextLong();
          	    if(A[i]==0){
            	    ans=0;
                }
    	    } {
    		    A[i]=sc.nextLong();
          	    if(A[i]==0){
            	    ans=0;
                }
    	    } A[i]=sc.nextLong() A[i] A i sc.nextLong() sc.nextLong sc if(A[i]==0){
            	    ans=0;
                } A[i]==0 A[i] A i 0 {
            	    ans=0;
                } ans=0 ans 0 if(ans!=0){
		    	for(int i=0; i<N; i++){
            	if(A[i] <= (long)Math.pow(10,18)/ans){
                	ans *= A[i];
            	}else{
          	    	ans=-1;
                	break;
            	}
    		}
  	    } ans!=0 ans 0 {
		    	for(int i=0; i<N; i++){
            	if(A[i] <= (long)Math.pow(10,18)/ans){
                	ans *= A[i];
            	}else{
          	    	ans=-1;
                	break;
            	}
    		}
  	    } for(int i=0; i<N; i++){
            	if(A[i] <= (long)Math.pow(10,18)/ans){
                	ans *= A[i];
            	}else{
          	    	ans=-1;
                	break;
            	}
    		} int i=0; int i=0; i 0 i<N i N i++ i++ i {
            	if(A[i] <= (long)Math.pow(10,18)/ans){
                	ans *= A[i];
            	}else{
          	    	ans=-1;
                	break;
            	}
    		} {
            	if(A[i] <= (long)Math.pow(10,18)/ans){
                	ans *= A[i];
            	}else{
          	    	ans=-1;
                	break;
            	}
    		} if(A[i] <= (long)Math.pow(10,18)/ans){
                	ans *= A[i];
            	}else{
          	    	ans=-1;
                	break;
            	} A[i] <= (long)Math.pow(10,18)/ans A[i] A i (long)Math.pow(10,18)/ans (long)Math.pow(10,18) Math.pow Math 10 18 ans {
                	ans *= A[i];
            	} ans *= A[i] ans A[i] A i {
          	    	ans=-1;
                	break;
            	} ans=-1 ans -1 1 break; System.out.println(ans) System.out.println System.out System System.out ans String[] args args public class Main{
    public static void main(String[] args){
	    Scanner sc=new Scanner(System.in);
            int N =sc.nextInt();
  		    long[] A = new long[N];
  		    long ans=1;
		    for(int i=0; i<N; i++){
    		    A[i]=sc.nextLong();
          	    if(A[i]==0){
            	    ans=0;
                }
    	    }
  	    	if(ans!=0){
		    	for(int i=0; i<N; i++){
            	if(A[i] <= (long)Math.pow(10,18)/ans){
                	ans *= A[i];
            	}else{
          	    	ans=-1;
                	break;
            	}
    		}
  	    }
    	System.out.println(ans);
    }
} public class Main{
    public static void main(String[] args){
	    Scanner sc=new Scanner(System.in);
            int N =sc.nextInt();
  		    long[] A = new long[N];
  		    long ans=1;
		    for(int i=0; i<N; i++){
    		    A[i]=sc.nextLong();
          	    if(A[i]==0){
            	    ans=0;
                }
    	    }
  	    	if(ans!=0){
		    	for(int i=0; i<N; i++){
            	if(A[i] <= (long)Math.pow(10,18)/ans){
                	ans *= A[i];
            	}else{
          	    	ans=-1;
                	break;
            	}
    		}
  	    }
    	System.out.println(ans);
    }
} Main
import java.util.*; 
 
public class Main{
    public static void main(String[] args){
	    Scanner sc=new Scanner(System.in);
            int N =sc.nextInt();
  		    long[] A = new long[N];
  		    long ans=1;
		    for(int i=0; i<N; i++){
    		    A[i]=sc.nextLong();
          	    if(A[i]==0){
            	    ans=0;
                }
    	    }
  	    	if(ans!=0){
		    	for(int i=0; i<N; i++){
            	if(A[i] <= (long)Math.pow(10,18)/ans){
                	ans *= A[i];
            	}else{
          	    	ans=-1;
                	break;
            	}
    		}
  	    }
    	System.out.println(ans);
    }
}