text: import numpy as np
  import pandas as pd
  import matplotlib.pyplot as plt
  import math
  
  ts = []
  n = 1900
  s = 10
  for t in range(0,10000):
      a = math.exp(-(t*s**2/n))
      b = math.cos(math.pi**2/s*t)*n/4+n*3/4
      y = (a*b)//1
      ts.append(y)
      if y==1:
          break
  print(min(ts),max(ts))
  plt.plot(ts)
  plt.show()
  