/BACO - Bàn cờ

              Uses Crt;
        Var     cv:array[-trunc(1e4)..trunc(1e4),-trunc(1e4)..trunc(1e4)] of byte;
                a,b,c,d,i,j,res:longint;
        Begin
                readln(a,b,c,d); cv[c,d]:=1;
                for i:=1 to 8 do cv[a,i]:=1; for i:=1 to 8 do cv[i,b]:=1;
                for i:=1 to 8 do cv[c+i,d+i]:=1;
                for i:=1 to 8 do cv[c-i,+d-i]:=1;
                for i:=1 to 8 do cv[c-i,d+i]:=1;
                for i:=1 to 8 do cv[c+i,d-i]:=1;
                //for i:=1 to 8 do begin writeln; for j:=1 to 8 do write(cv[i,j]); end;
                for i:=1 to 8 do for j:=1 to 8 do if cv[i,j]=1 then inc(res);
                writeln(res);
                readln;
        End.