/in/foo.cc: In function 'int main()':
/in/foo.cc:79:31: warning: format '%d' expects argument of type 'int', but argument 2 has type 'll {aka long long int}' [-Wformat=]
  if(!n)return printf("%d\n",x0)&0;
                               ^
/in/foo.cc: In function 'll read()':
/in/foo.cc:9:15: warning: 'c' is used uninitialized in this function [-Wuninitialized]
  for(;!isdigit(c);c=getchar());
        ~~~~~~~^~~