art.cpp:5:6: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
main(){
^
art.cpp: In function 'int main()':
art.cpp:7:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%lld",&n);
~~~~~^~~~~~~~~~~
art.cpp:10:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%lld%lld",&a[i].first,&a[i].second);
~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~