// Arup Guha
// 2/26/2010
// This program calculates the distance between two points on the Cartesian
// plane.

int main() {
    
    double x1, y1, x2, y2;
    
    // Get the coordinates of the two points.
    printf("Enter the coordinates of the first point.\n);
    scanf("%lf%lf", &x1, &y1);
    
    printf("Enter the coordinates of the second point.\n");
    scanf("%lf%lf", &x2, &y2);
    
    // Calculate the distance between the two points, using
    // the standard formula.
    double dist = sqrt(pow(x1-x2, 2) + pow(y1-y2, 2));
    
    // Print out the result.
    printf("The distance between (%lf,%lf) and ", x1, y1);
    printf("(%lf,%lf) is %lf.\n", x2, y2, dist);
    
    return 0;
}