Для каждого столбца матрицы с чётным номером найти сумму его элементов

program Lab1_2;
  const  n= 5; m=5;
  var  a:array[1..n,1..m] of real;
       s,i,j:integer;

begin
  randomize;
   for i:=1 to n do
     begin
       for j:=1 to m do
         begin
          a[i,j]:=random(10);
          write(a[i,j]:4);
         end;
        writeln;
     end;
  s:=0;
   for i:=1 to n do begin
    for j:=1 to m do begin
     if (a[i,j] mod 2) = 0 then begin
      s:=s+a[i,j];
     end;
    end;
     end;
  writeln('summa: ',s);
   readln;
end.

Uses
 CRT;
Const
 nmax=20;
var
 A:array[1..nmax,1..nmax] of integer;
 i,j,n,m:integer;
 sum:real;
Begin
repeat
 Write('Vvedite kol-vo strok: ');
 Readln(n);
until n in [1..nmax];
repeat
 Write('Vvedite kol-vo stolbcov: ');
 Readln(m);
until m in [1..nmax];
randomize;
FOR i:= 1 to n DO
 begin
  FOR j:=  1 to m DO
   begin
    a[i,j]:=random(10)-2;
    write(a[i,j]:3);
   end;
  writeln;
 end;
FOR j:= 1 to m DO
 begin
 sum:=0;
  if j mod 2=0 then
  begin
  FOR i:=  1 to n DO
   sum:=sum+a[i,j];
  writeln('Сумма элементов ',j,'-го столбца:=',sum)
  end
 end;
Readln
End.

 program lab1_2;
const   n=5;m=4;
  type ta=array[1..n,1..m] of real;
  t=array[1..m] of real;
  var a:ta;
     f1,f2: file of real;

procedure sozd;
 var a:ta;
     i,j:integer;
  begin
   rewrite(f1);
    for i:=1 to n do
     for j:=1 to m do
      begin
        write ('a[',i,', ',j,']=');
        readln(a[i,j]);
        write(f1, a[i,j]);
      end;
  close(f1);
 end;

 procedure vvod(var a:ta);
 var i,j:integer;
  begin
  reset (f1);
 for i:=1 to n do
 begin
 for j:=1 to m do
 begin
  read (f1, a[i,j]);
write (a[i,j]:7:1,  ' ');
 end;
 writeln;
end;
 close(f1);
readln;
end;

procedure obrabotka(var a:ta);
var i,j: integer;
sum : real;
begin
j:=  n div 2;
for j := 1 to n do begin
sum:=0;
for I:= 1 to  m do begin
sum:= sum + a[i,j];
end;
end;end;


procedure vivod (var a:ta);
var i,j:integer;
 begin
rewrite(f2);
for i:=1 to n do begin
for j:=1 to m do begin
write (f2, a[i,j]);
write (a[i,j] :7:1, ' ');
end;writeln;
end;
close (f2);
readln;
end;
begin
assign (f1 , 'c:\lab1\in.dat');
assign (f1 , 'c:\lab1\out.dat');
sozd;
vvod(a);
obrabotka(a);
vivod(a);
end.