foo.cc: In function 'int main()':
foo.cc:6:3: error: 'longlong' was not declared in this scope
    6 |   longlong A,B;
      |   ^~~~~~~~
foo.cc:7:8: error: 'A' was not declared in this scope
    7 |   cin>>A>>B;
      |        ^
foo.cc:7:11: error: 'B' was not declared in this scope
    7 |   cin>>A>>B;
      |           ^

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