foo.cc: In function 'int main()':
foo.cc:39:23: warning: unknown conversion type character '\x0a' in format [-Wformat=]
   39 |         printf("%.2f\%\n", ret1);
      |                       ^~
foo.cc:40:23: warning: unknown conversion type character '\x0a' in format [-Wformat=]
   40 |         printf("%.2f\%\n", ret2);
      |                       ^~
foo.cc:41:23: warning: unknown conversion type character '\x0a' in format [-Wformat=]
   41 |         printf("%.2f\%\n", ret3);
      |                       ^~
foo.cc:42:23: warning: unknown conversion type character '\x0a' in format [-Wformat=]
   42 |         printf("%.2f\%\n", ret4);
      |                       ^~

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