составьте блок-схему по программе пожалуйста)

TYPE MAT=ARRAY [1..20,1..20] OF REAL;
VEC=ARRAY [1..20] OF REAL;
VAR A:MAT;
X:VEC;
I,N:INTEGER;
S:REAL;
PROCEDURE MATR(N:INTEGER; VAR A:MAT);
VAR I,J:INTEGER;
BEGIN FOR I:=1 TO N DO
FOR J:=1 TO N+1 DO BEGIN
WRITE('A',I:2,j:2,'?') ; READLN(A[ I,J])
END
end;
procedure gauss(n: integer ; var a:mat;var x:vec;Var s:real);
VAR I,J,K,L,K1,N1:INTEGER; R: REAL;
BEGIN N1:=N+1;
FOR K:= 1 TO N DO BEGIN K1:=K+1; S:=A[K,K]; J:=K;
FOR I:=K1 TO N DO BEGIN R:=A[I,K];
IF ABS(R)>ABS(S) THEN BEGIN S:=R; J:=I END
END;
IF S=0.0 THEN EXIT;
IF J<>K THEN FOR I:=K TO N1 DO BEGIN
R:=A[K,I]; A[K,I]:=A[J,I]; A[J,I]:=R END;
FOR J:=K1 TO N1 DO A[K,J]:=A[K,J]/S;
FOR I:=K1 TO N DO BEGIN R:=A[I,K];
FOR J:=K1 TO N1 DO A[I,J]:=A[I,J]-A[K,J]*R
END
end;
IF S<>0.0 THEN
FOR I:=N DOWNTO 1 DO BEGIN S:=A[I,N1];
FOR J:=I+1 TO N DO S:=S-A[I,J]*X[J];
X[I]:=S
END
END;
BEGIN
REPEAT WRITE ('N') ; READLN(N); MATR(N,A); GAUSS (N, A, X , S);
IF S<>0.0 THEN FOR I:=1 TO N DO WRITELN ('X' , I:2, ' = ' , X[I])
ELSE WRITELN('DET=0')
UNTIL FALSE
END.