import math
import sys

def fv(v0, a, n, dt):
    v=v0
    for i in range(0, n):
        v=v+a*dt
    return v


def fPhi(Phi0, v0, n, dt):
    Phi=Phi0
    for i in range(0, n+1):
        a=fa(Phi)
        v=fv(v0, a, i, dt)
        Phi=Phi+v*dt
    return Phi

def fa(Phi):
    a=math.sin(Phi)/0.314**2
    return a



dt=0.01
Phi0=float(sys.argv[1])
v0=0

n=0
Phi=fPhi(Phi0, v0, n, dt)
while(Phi<math.pi/2):
    print(n, "=>", Phi, "--- t=", n*dt, "s")
    n+=1
    Phi=fPhi(Phi0, v0, n, dt)
    
print(math.pi/2)