this is a program to insert data in binary tree but time limit exceed

this is a code to insert data into a binary tree but it exceed time limit , input would be as follows
First line contains two integers, T and X, number of nodes in the tree and value of the root.
Each detail of node contains two lines. First lines contains a string and second line contains an integer, which denotes the path of the node and the value of the node respectively.
String consists of only L or R. L denotes left child and R denotes right child
5 1
L
2
R
3
LL
4
LR
5

 #include<bits/stdc++.h>

using namespace std;

class Node{
    public:
    int x;
    Node*left,*right;
    Node(int data){
        x=data;
        left=NULL;
        right=NULL;
    }
};

void insert(Node*root,string s,int data)
{
    if(root==NULL) return;
     if(s[0]=='L')
     {
         root->left->x=data;
         root=root->left;
         return;
     }
     if(s[0]=='R'){
     root->right->x=data;
      root=root->right;
      return;
     }
     else
     insert(root,s.substr(1),data);
}

void preorder(Node*root){
    cout<<root->x<<" ";
    preorder(root->left);
    preorder(root->right);
}

 
int main()
{
    int n,x;
    cin>>n>>x;
    Node*root=new Node(x);
    while(n--)
    {
        string s; cin>>s;
        int data; cin>>data;
        insert(root,s,data);
    }
    preorder(root);

}