Var i, sum, n: integer;
Begin
Read(n);
for i := 0 to n do
if (i mod 2 =0) then sum := sum +i;
writeln(sum);
End.
Const
N = 3;
Var
A:Array[1..N,1..N] of integer;
i,j:integer;
Begin
Randomize;
WriteLn('Исходный массив:');
For i:= 1 to N do
Begin
For j:= 1 to N do
Begin
A[i,j]:=random(21)-10;
Write(A[i,j]:3,' ')
End;
WriteLn
End;
WriteLn('↓↓↓↓↓↓↓↓↓↓↓↓↓');
For i:= 1 to N do
A[i,i]:=5;
For i:= 1 to N do
Begin
For j:= 1 to N do
Write(A[i,j]:3,' ');
WriteLn
End;
End.