Program Tema;
var a:array[1..20,1..20] of integer;
i,j,s,n:integer;
Begin
s:=0;
writeln('Introduceti dimensiunea matricii:');
readln(n);
writeln('Introduceti matricea:');
for i:=1 to n do
begin
for j:=1 to n do
begin
read(a[i][j]);
if i+j<>n+1 then
s:=s+a[i][j];
end;
readln;
end;
writeln('Suma elementelor care nu sunt pe diagonala secundara este: ',s);
End.