/in/foo.cc: In function 'int Kth(int, int)':
/in/foo.cc:56:7: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   if(l>=match[top[u]].size()) return 0;
      ~^~~~~~~~~~~~~~~~~~~~~~
/in/foo.cc:60:8: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   if(-l>=shit[top[u]].size())return 0;
      ~~^~~~~~~~~~~~~~~~~~~~~
/in/foo.cc: At global scope:
/in/foo.cc:67:6: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
 main(){
      ^