marks={'raj':90,'harsh':70,'aman':30}
print(marks['raj'])

print(marks['aman'])

del(marks['harsh'])


print(marks.keys())

print(marks.values())

print('harsh' in marks)
marks={'raj':90,'harsh':70,'aman':30}
print(marks['raj'])

print(marks['aman'])

del(marks['harsh'])


print(marks.keys())

print(marks.values())

print('harsh' in marks)