uses crt;
var a,b,c:real;
kt:integer;
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 (a+c>b) and (b+c>a) then
begin
kt:=0;
if (a=b) and (a<>c) and (b<>c) then kt:=1;
if (b=c) and (b<>a) and (c<>a) then kt:=1;
if (c=a) and (c<>b) and (a<>b) then kt:=1;
if kt=0 then writeln('Day khong la tam giac can')
else writeln('Day la tam giac can');
end
else writeln('Day khong la ba canh trong mot tam giac');
readln;
end.