#!/usr/bin/env python3
# -*- coding: utf-8 -*-
PI=3.1415
def S(r):
    return PI*r*r

r1=12.34
r2=9.08
r3=73.1

print( 'S1=%.2f'%S(r1))
print( 'S2=%.2f'%S(r2))
print( 'S3=%.2f'%S(r3))