foo.cc: In function 'int main()':
foo.cc:6:9: warning: unused variable 'NA' [-Wunused-variable]
    6 |  int N, NA, NB;
      |         ^~
foo.cc:6:13: warning: unused variable 'NB' [-Wunused-variable]
    6 |  int N, NA, NB;
      |             ^~
foo.cc:10:6: warning: unused variable 'A' [-Wunused-variable]
   10 |  int A = 0, B = 0, i, j;
      |      ^
foo.cc:10:13: warning: unused variable 'B' [-Wunused-variable]
   10 |  int A = 0, B = 0, i, j;
      |             ^
foo.cc:10:23: warning: unused variable 'j' [-Wunused-variable]
   10 |  int A = 0, B = 0, i, j;
      |                       ^

[Hydro](https://hydro.ac)提供评测服务