uses crt;
var a,b,c:real;
begin
clrscr;
repeat
write('Nhap a='); readln(a);
write('Nhap b='); readln(b);
write('Nhap c='); readln(c);
until (a>0) and (b>0) and (c>0);
if (a+b>c) and (b+c>a) and (a+c>b) then
begin
if sqr(a)=sqr(b)+sqr(c) then writeln('Vuong')
else if sqr(b)=sqr(a)+sqr(c) then writeln('Vuong')
else if sqr(c)=sqr(a)+sqr(b) then writeln('Vuong')
else writeln('La tam giac khong vuong');
end
else writeln('Khong la ba canh trong mot tam giac');
readln;
end.