foo.cc: In function 'int main()':
foo.cc:8:18: warning: unknown conversion type character ',' in format [-Wformat=]
    8 |         printf("%,1f",c);
      |                  ^
foo.cc:8:16: warning: too many arguments for format [-Wformat-extra-args]
    8 |         printf("%,1f",c);
      |                ^~~~~~

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