foo.cc: In function 'int main()':
foo.cc:9:32: warning: unused variable 'a' [-Wunused-variable]
    9 |         int n = letter.size(), a = 0, b = 0, count = 0;
      |                                ^
foo.cc:9:39: warning: unused variable 'b' [-Wunused-variable]
    9 |         int n = letter.size(), a = 0, b = 0, count = 0;
      |                                       ^

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