import math
def calculate_area_of_intersection(center1, center2, radius1, radius2):
"""Calculates the area of intersection of two circles.
Args:
center1: A tuple containing the coordinates of the center of the first circle.
center2: A tuple containing the coordinates of the center of the second circle.
radius1: The radius of the first circle.
radius2: The radius of the second circle.
Returns:
The area of intersection of the two circles, rounded up to 6 decimal places.
"""
distance = math.sqrt((center1[0] - center2[0])**2 + (center1[1] - center2[1])**2)
if distance > radius1 + radius2:
return 0
elif distance < radius1 - radius2:
return math.pi * radius2**2
else:
theta1 = 2 * math.acos((radius1**2 + distance**2 - radius2**2) / (2 * radius1 * distance))
theta2 = 2 * math.acos((radius2**2 + distance**2 - radius1**2) / (2 * radius2 * distance))
area_of_intersection = 0.5 * (theta1 * radius1**2) - 0.5 * (radius1**2 * math.sin(theta1)) + 0.5 * (theta2 * radius2**2) - 0.5 * (radius2**2 * math.sin(theta2))
return round(area_of_intersection, 6)
def main():
"""Calculates the area of intersection of two circles."""
# Input the coordinates and radii of the two circles.
center1 = (int(input()), int(input()))
radius1 = int(input())
center2 = (int(input()), int(input()))
radius2 = int(input())
# Calculate the area of intersection.
area_of_intersection = calculate_area_of_intersection(center1, center2, radius1, radius2)
# Output the area of intersection.
print(area_of_intersection)
if __name__ == '__main__':
main()