postmen.cpp: In function 'int main()':
postmen.cpp:53:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%d %d", &n, &m);
~~~~~^~~~~~~~~~~~~~~~~
postmen.cpp:58:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%d %d", &n, &m);
~~~~~^~~~~~~~~~~~~~~~~
postmen.cpp:57:7: warning: 'u' may be used uninitialized in this function [-Wmaybe-uninitialized]
int u, v;
^
postmen.cpp:57:10: warning: 'v' may be used uninitialized in this function [-Wmaybe-uninitialized]
int u, v;
^