from math import radians, sin, cos, acos  
  
print("Input coordinates of two points:")  
slat = radians(float(input("Starting latitude: ")))  
slon = radians(float(input("Ending longitude: ")))  
elat = radians(float(input("Starting latitude: ")))  
elon = radians(float(input("Ending longitude: ")))  
  
dist = 6371.01 * acos(sin(slat)*sin(elat) + cos(slat)*cos(elat)*cos(slon - elon))  
print("The distance is %.2fkm." % dist)