foo.cc: In function 'int main()':
foo.cc:6:2: error: expected ',' or ';' before 'scanf'
  scanf("%d", &a);
  ^~~~~
foo.cc:17:2: error: expected ';' before '}' token
  }
  ^
foo.cc:21:2: error: expected ';' before '}' token
  }
  ^

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