/in/foo.cc:3:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
    3 | main()
      | ^~~~
/in/foo.cc: In function 'int main()':
/in/foo.cc:33:8: warning: 'd' may be used uninitialized [-Wmaybe-uninitialized]
   33 | if(c&&d==i)
      |       ~^~~
/in/foo.cc:5:33: note: 'd' was declared here
    5 | int k,x,i,sum=0,y,a[101],b[101],d;
      |                                 ^