/in/foo.cc:18:0: warning: "LONG_LONG_MIN" redefined
 #define LONG_LONG_MIN -9223372036854775808ll
 
In file included from /in/foo.cc:5:0:
/usr/lib/gcc/x86_64-linux-gnu/6/include-fixed/limits.h:152:0: note: this is the location of the previous definition
 # define LONG_LONG_MIN (-LONG_LONG_MAX - 1LL)
 
/in/foo.cc:19:0: warning: "LONG_LONG_MAX" redefined
 #define LONG_LONG_MAX 9223372036854775807ll
 
In file included from /in/foo.cc:5:0:
/usr/lib/gcc/x86_64-linux-gnu/6/include-fixed/limits.h:154:0: note: this is the location of the previous definition
 # define LONG_LONG_MAX __LONG_LONG_MAX__
 
/in/foo.cc: In function 'int main()':
/in/foo.cc:99:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
 for(int i = 0; i < a.size(); ++i){
                ~~^~~~~~~~~~