Can someone say whats wrong in this code??

Question

Im new to python so i cant figure it out

vow=['a', 'e' , 'i' , 'o' , 'u']
wrd=input("enter ")

h=0

def f () :
for i in wrd:
for j in vow:
if i==j :
h=h+1

f()
print("No. of vowels = " , h)