Error int object is not subscriptable - Python

Question

I was trying a program in which you input someone's name and age and then it lets you know when they turn 21.  But I keep getting this error:  'int' object is not subscriptable.

My code.

name1 = raw_input("What's your name? ")
age1 = raw_input ("how old are you? ")
x = 0
int([x[age1]])
twentyone = 21 - x
print "Hi, " + name1+ " you will be 21 in: " + twentyone + " years."

Any help would be greatly appriciated.