/in/foo.cc: In function 'int main()':
/in/foo.cc:60:9: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  if(t-kk>kk)kk=t-kk;
     ~~~~^~~
/in/foo.cc:61:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=1;i<=t-kk;i++)
              ~^~~~~~
/in/foo.cc:63:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(ull i=t;i>kk;i--)
              ~^~~
/in/foo.cc:66:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int j=1;j<=t-kk;j++)
               ~^~~~~~