print distance(60.1843160, -128.5069940, 29.46786, -98.53506, "M"), " miles\n";
print distance(32.9697, -96.80322, 29.46786, -98.53506, "K"), " kilometers\n";
print distance(32.9697, -96.80322, 29.46786, -98.53506, "N"), " nautical miles\n";