const n=5;
var a:array[1..n,1..n] of integer;
i,j,min,im,jm:integer;
begin
Randomize; 
for i:=1 to n do
 begin
  for j:=1 to n do
   begin
   a[i,j]:=random(20)-10;
   write(a[i,j]:4); 
  end;
  writeln;
  end; 
min:=a[1,1]; im:=1; jm:=1;
for i:=1 to n do
 for j:=1 to n do 
  if ((i+j)mod 2 =0)and(a[i,j]<min) then 
  begin
   min:=a[i,j]; im:=i; jm:=j;
  end;
writeln('min=a[',im,',',jm,']=',min);
end.

Пример:
   8  -6   0  -2   4
   3   6   0   9   2
  -1  -6   6   6   6
 -10  -2   8  -6  -2
   7   2   6   3  -8
min=a[5,5]=-8