foo.cc: In function 'int main()':
foo.cc:7:9: error: 'cin' was not declared in this scope; did you mean 'std::cin'?
    7 |         cin>>a>>k;
      |         ^~~
      |         std::cin
In file included from stdc++.h:75:
/nix/store/1x1q5sqa0ilbi8fz7aayk02pjy5g7jhh-gcc-12.3.0/include/c++/12.3.0/iostream:60:18: note: 'std::cin' declared here
   60 |   extern istream cin;           /// Linked to standard input
      |                  ^~~
foo.cc:8:19: warning: unknown conversion type character 'k' in format [-Wformat=]
    8 |         printf("%.klf",a);
      |                   ^
foo.cc:8:16: warning: too many arguments for format [-Wformat-extra-args]
    8 |         printf("%.klf",a);
      |                ^~~~~~~

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