# Online Python compiler (interpreter) to run Python online.
# Write Python 3 code in this online editor and run it.
import tkinter
import random

list_b=[[],[],[],[],[]]
for i in range (5):
    for j in range (5):
        list_b[i].append(Label(tk, bg = 'lightblue', width = 4))
        list_b[i][j].grid(row = i, column = j, padx = 2, pady = 2)

def output():
    for i in range (5):
        for j in range (5):
            list_b[i][j].config(text = str(a[i][j]))

Label(tk, text = 'Координати верхнього лівого кута:').grid(row = 5,column = 0, columnspan = 5)
enx1 = Entry(tk, width = 3)
enx1.grid(row = 6, column = 1)
eny1=Entry(tk, width = 3)
eny1.grid(row = 6, column = 3)

envart = Entry(tk, width = 6)
envart.grid(row = 10, column = 2)

but = Button(text = 'Обчислити', command = but_click, width =14).grid(row = 9, column = 0, columnspan = 5)

def but_click():
    x1 = int(enx1.get())
    y1 = int(eny1.get())
    x2 = int(enx2.get())
    y2 = int(eny2.get())
    vart = 0
    for i in range(x1, x2+1):
        for j in range(y1, y2+1):
            vart = vart+a[i][j]
    envart.delete(0, END)
    envart.insert(0, str(vart))

tk.mainloop()