foo.cc: In function 'int main()':
foo.cc:8:19: warning: unknown conversion type character 'k' in format [-Wformat=]
    8 |         printf("%.kf",a);
      |                   ^
foo.cc:8:16: warning: too many arguments for format [-Wformat-extra-args]
    8 |         printf("%.kf",a);
      |                ^~~~~~