#include<stdio.h>
#include<stdlib.h>
typedef struct node{
    int data;
    struct node*left,*right;
    
}a;
a*root=NULL;
a*create(int num){
    a*newnode=(a*)malloc(sizeof(a));
    newnode->data=num;
    newnode->left=NULL;
    newnode->right=NULL;
    return newnode;
}
a*ins(a*root,int num){
    if(root==NULL)
        return create(num);
    if(num<root->data)
        root->left=ins(root->left,num);
    else if(num>root->data)
        root->right=ins(root->right,num);
    return root;
}
a*min(a*root){
    if(root==NULL)
        return root;
    if(root->left!=NULL)
        return min(root->left);
    return root;
}
a*search(a*root,int num){
    if(root==NULL || root->data==num)
    return root;
    if(num<root->data){
        return search(root->left,num);
        return search(root->right,num);
    }
    
    
}
a*del(a*root,int num){
    if (root==NULL)
        return root;
    if (num<root->data){
        root->right=del(root->right,num);
    }
    else if(num>root->data){
    root->left=del(root->left,num);        
    }
    else{
        if(root->left==NULL&&root->right==NULL){
            return NULL;
        }
        else if(root->left!=NULL && root->right==NULL){
            return root->left;
        }
        else if(root->left==NULL && root->right!=NULL){
            return root->right;
        }
        else{
            a*temp=min(root->right);
            root->data=temp->data;
            root->right=del(root->right,temp->data);
            
        }
    }return root;
}
void inorder(a*root){
    if(root!=NULL){
        inorder(root->left);
        printf("%d",root->data);
        inorder(root->right);
    }
}
int main(){
    int s,i,n,k;
    scanf("%d",&s);
    for(i=0;i<s;i++){
        scanf("%d",&n);
        root=ins(root,n);
    }
    scanf("%d",&k);
    if(search(root,k)==NULL){
        printf("-1");
        return 0;
    }
    root=del(root,k);
    inroder(root);
    return 0;
}
    
}