Có ai giỏi lập trình pascal không giúp mình với

program merge_algorithm;
uses crt;
var a: array[1..100] of integer;
 b: array[1..100] of integer;
 na,nb: integer; {na: length of array A, nb: length of array B}

 c: array[1..200] of integer;
 nc: integer; {nc: length of array C}

 input_file: text;
 output_file: text;

 i, j, k: integer;

begin
 {Initialization}
 assign(input_file, 'sn.dat');
 reset(input_file);

 assign(output_file, 'snc.dat');
 rewrite(output_file);

 {copy data into array A}
 na := 0;
 while not eoln(input_file) do
 begin
 na := na + 1;
 read(input_file, a[na]);
 end;

 {copy data into array B}
 nb := 0;
 readln(input_file);
 while not eoln(input_file) do
 begin
 nb := nb + 1;
 read(input_file, b[nb]);
 end;

 close(input_file);

 {merge algorithm}
 i := 1; {Index of array A}
 j := 1; {Index of array B}
 k := 1; {Index of array C}
 nc := na + nb; {length of array C is sum of length of array A and array B}
 while (i <= na) and (j <= nb) do
 begin
 if a[i] <= b[j] then
 begin
 c[k] := a[i];
 i := i + 1;
 end
 else
 begin
 c[k] := b[j];
 j := j + 1;
 end;

 k := k + 1;
 end;

 if i <= na then
 for i := i to na do
 begin
 c[k] := a[i];
 k := k + 1;
 end;

 if j <= nb then
 for j := j to nb do
 begin
 c[k] := b[j];
 k := k + 1;
 end;
 {copy array C into file "snc.dat"}
 for i := 1 to nc do
 write(output_file, c[i], ' ');

 close(output_file);
end.

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