// Written by Hosung Leo Kim

#include <iostream>
#include <cmath>


int getInput()
{
  int value;

  cout << "1 or 2? ";
  cin >> value;

  return value;
}


void lineLength()
{
  int x1, y1, x2, y2;

  cout << "x1 y1 x2 y2? ";
  cin >> x1 >> y1 >> x2 >> y2;

  cout << sqrt( pow( ( x2 - x1 ), 2 ) + pow( ( y2 - y1 ), 2 ) ) << endl;
  
  return;
}


int main()
{
  int choice;

  choice = getInput();

  switch ( choice )
  {
    case 1:
      cout << "You chose 1" << endl;
      lineLength();
      break;
    case 2:
      cout << "You chose 2" << endl;
  }

  return 0;
}