a=input('enter value  ')
b,c=input('enter two values  ')
print a
print b
print c
print a,b,c
print 'if else demo '
if a==20:
    print a
else:
    print 'not 20'

        
print '------'
if a==20 and b>20:
    print a
elif a<20 and b>20:
    print b
else:
    print 'nothing'
print '------while loop ------'
f=1
i=1
n=input('enter number  ')
while i<=n:
    f=f*i
    i=i+1
print 'factorial is ',f

