pc.cpp: In function 'int main()':
pc.cpp:6:9: warning: unused variable 'j' [-Wunused-variable]
int i, j, k, l;
^
pc.cpp:6:15: warning: unused variable 'l' [-Wunused-variable]
int i, j, k, l;
^
pc.cpp:7:24: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%d %d", &n, &m);
^
pc.cpp:9:25: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%lld", &a[n-i]);
^