model;
param n:=3;
param s:=n*n;
set I:=1..n;
set J:=1..n;
set K:=1..n*n;
var y {I, J, K} binary;
var constant integer;


minimize Magic_Constant: constant;

subject to OneEach {i in I, j in J}: sum {k in K} y[i,j,k] = 1;
subject to AllDifferent {k in K}: sum {i in I, j in J} y[i,j,k] <= 1;
subject to RowsSum {i in I}: sum {j in J, k in K} k*y[i, j, k] = constant;
subject to ColsSum {j in J}: sum {i in I, k in K} k*y[i, j, k] = constant;
subject to Diag: sum {i in I, k in K} k*y[i, i, k] = constant;
subject to ADiag: sum {i in I, k in K} k*y[i, n-i+1, k] = constant;
subject to q1: ((n*n)/2)*(n*n+1) = constant*n;