Joy is a twelfth grade student who is aiming to go to SUSTech. One day, when he is doing math practices. He found a problem very hard. It gives a function goes like F(x) = 5x7+6x6+3x3+4x2-2xy (0 <= x <=100), y is a given real number. Can you help Joy find the minimum value of F(x) when x is in its domain?