t=0
while t!=3:
print("""Choose the operation:
1.Search and Show
2.Change String
3.Exit""")
t=int(input("Enter the operation number = "))
if t==3:
break
elif t==1:
k=0
s=input("Enter characters to search = ")
for i in n.split():
str(i)
if s==i[0:len(s)]:
print(i)
k=1
if k==0:
print("NO WORD FOUND")
elif t==2:
n=input("Enter a string = ")
print()