d={}
#entry
s=int(input("enter how many records"))
for i in range(s):
    r=int(input("enter rollno"))
    n=input("enter name")
    d[r]=n

#display
for i in d:
    print(i,d[i])

#deletion
a=int(input("enter rollno which u want to delete"))
del d[a]
for i in d:
    print(i,d[i])

#update
a=int(input("enter rollno which u want to update"))
v=input("enter the value")
d[a]=v
for i in d:
    print(i,d[i])

#search
a=int(input("enter rollno which u want to display"))
for i in d:
    if i==a:
        print(i,d[i])


#deletion based searching
a=int(input("enter rollno which u want to delete"))
if a in d:
    print(i,d[i])
    d.pop(a)
    break
else:
    print("not found")
    break