#include <iostream>
using namespace std;

int main() {
  double height;

  do {
    cout << "Enter your height (in meters): ";
    cin >> height;
 
    if(height > 0)
      break;
      
    cerr << "Invalid height. Try again..." << endl;
  } while(true);
  
  cout << "You height is: " << height << " meters." << endl;
}