program triang;
var a, b, c, p, s: real;
begin
writeln('Input a >');
readln(a);
writeln('Input b >');
readln(b);
c:=sqrt(sqr(a)+sqr(b));
p:=a+b+c;
s:=(a*b)/2;
writeln('S=',s);
writeln('P=',p);
readln
end.