foo.cc: In function 'int main()':
foo.cc:6:3: error: invalid conversion from 'const char*' to 'int' [-fpermissive]
    6 | a="Hello World!"
      |   ^~~~~~~~~~~~~~
      |   |
      |   const char*
foo.cc:6:17: error: expected ';' before 'cout'
    6 | a="Hello World!"
      |                 ^
      |                 ;
    7 | cout<<a;
      | ~~~~             
foo.cc:5:5: warning: unused variable 'n' [-Wunused-variable]
    5 | int n,a;
      |     ^

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