Решение задачи File 19

import random

def GenerateLine(fname):
    N = random.randrange(1,10)
    print("N = ",N)
    #N = 2
    #line = "1, 5, 5, 5, 4, 4, 5"
    try:
        f = open(fname, "w")
        try:
            for i in range(N):
                line = str(random.randint(1,4))+"\n"
                f.write(line)
        finally:
            f.close()
    except IOError:
        print('Write error: ',fname)

f_input = "file19_input.txt"
GenerateLine(f_input)

i = 0
flag = False
try:
    with open(f_input,'r') as f_in:
        for line in f_in:
            i += 1
            x = int(line.strip())
            print(x)    
            if i == 1:
                x1 = x
            elif i == 2:
                x2 = x
            elif i == 3:
                x3 = x
                if x3 >= x2:
                    l_max_prev = x3
                elif x1 <= x2 and x2 > x3:
                    l_max_prev = x2
                else:
                    l_max_prev = x1
            else:
                x1 = x2
                x2 = x3
                x3 = x
                if x3 >= x2:
                    l_max_next = x3
                elif x1 <= x2 and x2 > x3:
                    l_max_next = x2
                else:
                    l_max_next = l_max_prev

except IOError:
    print('Open error: ',f_source)
        
if i == 1:
    l_max = x1
elif i == 2:
    if x1 > x2:
        l_max = x1
    else:
        l_max = x2
elif i == 3:
    l_max = l_max_prev
else:
    l_max = l_max_next
    
print("Last local maximum:",l_max)
									

program File19;
var
 S:String;
 F_in,F_out: File of Real;
 El2,El1,El,LocMax:Real;
begin
  Write('File: ');
  Readln(S);
  Assign(F_in,S);
  Reset(F_in);
  Read(F_in,El1);
  Read(F_in,El);
  El2:=El1;
  if (El1>El) then LocMax:=El1;
  while (not eof(F_in)) do
   begin
    El2:=El1;
    El1:=El;
    Read(F_in,El);
    if (El<El1) and (El1>El2) then LocMax:=El1;
   end;
  if El1<El then LocMax:=El;
  Writeln(LocMax);
  Close(F_in);
end.