uses crt;
const nmax=20;
var t:array[1..nmax,1..nmax] of integer;
m,n,i,j:byte;
begin
clrscr;
randomize;
repeat
write('Количество строк до ',nmax,' n=');
readln(n);
until n in [1..nmax];
repeat
write('Количество столбцов до ',nmax,' m=');
readln(m);
until m in [1..nmax];
writeln('Исходная матрица:');
for i:=1 to n do
begin
for j:=1 to m do
begin
t[i,j]:=random(20)+1;
write(t[i,j]:4);
end;
writeln;
end;
writeln;
for i:=2 to n do
for j:=2 to m do
if(i mod 2=0)and(j mod 2=0) then t[i,j]:=0;
writeln('Обнуление элементов на пересечениии четных строк и столбцов:');
for i:=1 to n do
begin
for j:=1 to m do
write(t[i,j]:4);
writeln;
end;
readln
end.