matryoshka.cpp: In function 'void dfs(int, int)':
matryoshka.cpp:15:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for (int i = 0; i < vt[here].size(); i++) {
~~^~~~~~~~~~~~~~~~~
matryoshka.cpp: In function 'int main()':
matryoshka.cpp:25:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%d %d", &n,&m);
~~~~~^~~~~~~~~~~~~~~~
matryoshka.cpp:28:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%d %d", &a[i].first, &a[i].second);
~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
matryoshka.cpp:40:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%d %d", &q, &w);
~~~~~^~~~~~~~~~~~~~~~~