/in/foo.cc: In function 'void sous2(int, int)':
/in/foo.cc:53:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=0;i<b[x].cs.size();i++){
              ~^~~~~~~~~~~~~~~
/in/foo.cc:56:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int j=0;j<c[y].cs.size();j++){
               ~^~~~~~~~~~~~~~~
/in/foo.cc:61:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int j=0;j<c[y].cs.size();j++){
               ~^~~~~~~~~~~~~~~