school.cpp:26:6: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
26 | main(){
| ^
school.cpp: In function 'int main()':
school.cpp:27:17: warning: unused variable 'j' [-Wunused-variable]
27 | int n,x,y,i,j,mx=0,sum=0;
| ^
school.cpp:13:27: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
13 | #define scan3(a,b,c) scanf("%lld %lld %lld",&a,&b,&c);
| ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
school.cpp:28:5: note: in expansion of macro 'scan3'
28 | scan3(n,x,y)
| ^~~~~
school.cpp:12:25: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
12 | #define scan2(a,b) scanf("%lld %lld",&a, &b);
| ~~~~~^~~~~~~~~~~~~~~~~~~~
school.cpp:32:9: note: in expansion of macro 'scan2'
32 | scan2(a,b)
| ^~~~~