foo.cc: In function 'int main()':
foo.cc:16:11: warning: unknown conversion type character ',' in format [-Wformat=]
   16 |  printf("%,2f",s);
      |           ^
foo.cc:16:9: warning: too many arguments for format [-Wformat-extra-args]
   16 |  printf("%,2f",s);
      |         ^~~~~~

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