foo.cpp: In function 'int main()':
foo.cpp:13:2: error: 'fin' was not declared in this scope
  fin>>l>>n>>m;
  ^
foo.cpp:53:2: error: 'fout' was not declared in this scope
  fout<<min;
  ^
foo.cpp:12:16: warning: unused variable 'k' [-Wunused-variable]
  int i,j,t,min,k;
                ^