A binary tree consists of int.

BinaryTree.java

public class BinaryTree {
    int i;
    BinaryTree right;
    BinaryTree left;
    
    public BinaryTree(int _i, BinaryTree _right, BinaryTree _left) {
        i =_i;
        right = _right;
        left = _left;
    }
    
    public int sumAll(){
        int ans = this.i;
        if(this.left != null){
            ans += this.left.sumAll();
        }
        if(this.right != null){
            ans += this.right.sumAll();
        }
        return ans;
    }
    
    @Override
    public String toString(){
        StringBuilder sb = new StringBuilder();
        sb.append("(");
        sb.append(this.i);
        if(this.left != null){
            sb.append(left.toString());
        }
        if(this.right != null){
            sb.append(right.toString());
        }
        sb.append(")");
        return sb.toString();
        
    }
    
}