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.