def convert_part_to_uppercase(s, idx) :
length = len(s)
if (idx < 0 or idx > length): return s
s = list(s)
for i in range(length) :
if (i >= idx and (ord(s[i]) >= 97 and ord(s[i]) <= 122)):
s[i] = chr(ord(s[i]) - 32)
return "".join(s)
s = "python programming"
s = convert_part_to_uppercase(s, 4)
print(s)
'''
run:
pythON PROGRAMMING
'''