/in/foo.cc: In function 'int main()':
/in/foo.cc:7:17: warning: 'i' is used uninitialized [-Wuninitialized]
    7 |         cin>>a[i];
      |              ~~~^
/in/foo.cc:6:30: note: 'i' was declared here
    6 |         long long max=0,sm=0,i,ii=0,i2=0;
      |                              ^