walls.cpp: In function 'int main()':
walls.cpp:16:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
16 | scanf("%d%d", &N, &M);
| ~~~~~^~~~~~~~~~~~~~~~
walls.cpp:17:31: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
17 | for(int i=1; i<=N; i++) scanf("%d%d", &A[i].first, &A[i].second);
| ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
walls.cpp:18:31: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
18 | for(int i=1; i<=M; i++) scanf("%d", &B[i]);
| ~~~~~^~~~~~~~~~~~~