foo.cc:7:23: warning: suggest parentheses around '+' inside '<<' [-Wparentheses]
 const int N=17,M=1<<15+5;
                     ~~^~
foo.cc: In function 'int main()':
foo.cc:40:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=0;i<state.size();i++){
              ~^~~~~~~~~~~~~
foo.cc:41:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int j=0;j<state.size();j++){
               ~^~~~~~~~~~~~~
foo.cc:53:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int j=0;j<state.size();j++){
               ~^~~~~~~~~~~~~
foo.cc:55:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    for(int k=0;k<head[a].size();k++){
                ~^~~~~~~~~~~~~~~

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