foo.cc: In function 'int main()':
foo.cc:4:27: warning: unused variable 'i' [-Wunused-variable]
    4 |         int a[4],t,n,cn=0,i=0;
      |                           ^
foo.cc:16:18: warning: 'a' may be used uninitialized [-Wmaybe-uninitialized]
   16 |         cout<<a[0]<<endl;
      |                  ^
foo.cc:4:13: note: 'a' declared here
    4 |         int a[4],t,n,cn=0,i=0;
      |             ^

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