cout << a->value->Char;

if (a->left != NULL)prefix(a->left);

if (a->right != NULL)prefix(a->right);

{

string str;

cout << "enter string" << endl;

getline(cin, str);

tree* test = ast(str);

if (test != NULL)

{

cout << "prefix: "; prefix(test->root); cout << endl;

}

}