View difference between Paste ID: Kxb9GYnV and DREc4hhm

 x = input()
 i = 0
 cnt = 1
-while (i < len(x)) :
+while (i <= len(x)) :
     if (x[i] == x[i+1]) :
         cnt = cnt + 1
     else:
         print(x[i], end='')
         print(cnt, end='')
 		cnt=1