/in/foo.cc: In function 'int main()':
/in/foo.cc:11:2: error: 'fin' was not declared in this scope
  fin>>n>>m>>k;
  ^~~
/in/foo.cc:16:2: error: 'fout' was not declared in this scope
  fout<<setprecision(6)<<1.0-jsq;
  ^~~~