/in/foo.cc: In function 'void read(num&)':
/in/foo.cc:22:8: warning: unused variable 'j' [-Wunused-variable]
  int i,j,k;
        ^
/in/foo.cc:22:10: warning: unused variable 'k' [-Wunused-variable]
  int i,j,k;
          ^
/in/foo.cc: In function 'void solve(int)':
/in/foo.cc:40:8: warning: unused variable 'j' [-Wunused-variable]
  int i,j,k;
        ^
/in/foo.cc:40:10: warning: unused variable 'k' [-Wunused-variable]
  int i,j,k;
          ^