foo.cc:6:20: warning: missing terminating ' character
    6 |     long long a,b,c'
      |                    ^
foo.cc:6:20: error: missing terminating ' character
foo.cc: In function 'int main()':
foo.cc:7:5: error: expected initializer before 'cin'
    7 |     cin >> a >> b >> c;
      |     ^~~
foo.cc:8:14: error: 'c' was not declared in this scope
    8 |     cout << (c - a - b) / 3;
      |              ^

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