//4)var x1, y1, x2, y2, x3, y3, x4, y4: integer; s, sc: real;function linelength(x1, y1, x2, y2: integer): real;begin linelength := sqrt(sqr(x2 - x1) + sqr(y2 - y1));end;procedure ger(a, b, c: real);var p: real;begin p := (a + b + c) / 2; sc := sqrt(p * (p - a) * (p - b) * (p - c));end;begin write('1:');readln(x1, y1); write('2:');readln(x2, y2); write('3:');readln(x3, y3); write('4:');readln(x4, y4); ger(linelength(x1, y1, x2, y2), linelength(x2, y2, x3, y3), linelength(x1, y1, x3, y3)); s := s + sc; ger(linelength(x1, y1, x4, y4), linelength(x4, y4, x3, y3), linelength(x1, y1, x3, y3)); s := s + sc; writeln(s);end.//3)var a, b, c: integer;function sce(var a: integer): integer;var sc, c: integer;begin while a <> 0 do begin c := a mod 10; a := a div 10; sc := sc + c; end; sce := sc;end;begin read(a, b, c); if (sce(a) > sce(b)) and (sce(a) > sce(c)) then writeln(a) else if (sce(b) > sce(a)) and (sce(b) > sce(c)) then writeln(b) else if (sce(c) > sce(a)) and (sce(c) > sce(b)) then writeln(c) else if (sce(c) = sce(a)) and (sce(a) = sce(b)) then writeln('Равны');end.