matrix := [
[Z(25)^3,0*Z(25),0*Z(25),0*Z(25)],
[0*Z(25),0*Z(25),Z(25)^24,0*Z(25)],
[Z(25)^21,Z(25)^12,Z(25)^3,0*Z(25)],
[0*Z(25),Z(25)^15,Z(25)^12,Z(25)^21]
];