[Kingroudy]

now here is the solution:
first i'm french educated so excuse me for "math-in-english" mistakes if there are any.
let x be the # of the month
we did the following to x:
(((4x+13)25-200)2-40)50-10500
= 10000x
let y be the # of the day of the month you were born
we did the following to y:
2y*50=100y
and finally we added z wich is the last two digits of the number of the year.
the final simplified equation is:
10000x+100y+z
the reason for choosing 1 , 100 , 10000 (multiplying by 100) is that x,y and z are 2-digit numbers.
simple huh?! yet funny!