Can anyone please help me to understand this code's operation.the result is 24 but how is it?

Question

def main():

    print(f(4))

def f(n):

    s=1

    for i in range(2,n+1):

        s=s*i

    return s

main() # Call the main function

The result is 24

Answer 1

2,5
1=1*2
=2
3,5
2=2*3
=6
4,5
6=6*4
=24

Was it difficult?