n = int(input("enter the number"))
i = 1
sume = 0 
while i <= n:
    if(i % 2 == 1):
        sume= sume + i
    i = i + 1
print("sum ",sume)

2nd question

Reverse a String without using slicing ([::-1]).

n = "cpandu"
lund = n[-1:-n:-1]
print(lund)

3rd program

Count vowels in a given string

name = "hello"
year = "aeiouAEIOU"
count = 0
for i in name:
 if i in year:
 count = count+1
print(the total number  of  vowel present in the sentance",count)

4th program

Find the largest number in a list without using max().

number = [1,2,3,4,5]
large = number[0]
for i in number:
    if i > large:
        large = i
print("largest number amoung this list ",i)

5th program

Check if a number is prime.

• prime number is a number that can divided only by 1 or itself

num = int(input("enter the any number"))
if num > 1:
    for i in range(2,num):
        if num % i ==0:
            print(num, "is not a prime number")
    else:
        print(num, "is a prime number")
else:
    print(num," is not a prime number")

6th program

• Sum of digits of a number (e.g., 123 → 6).

n = input("enter the number ")
total = 0
for i in str(n):
  total = total + int(i)
print(total)

7 th program