Write a function that returns True if you can use the letters of the first string to create the second string. Letters are case sensitive.
can_build("aPPleAL", "PAL") ➞ True
can_build("aPPleAL", "apple") ➞ False
can_build("a", "") ➞ True
can_build("aa", "aaa") ➞ False
Letters in the first string can be used only once.