/in/foo.cc: In function 'int main()':
/in/foo.cc:21:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    if ((n - c) <= ans)
        ~~~~~~~~^~~~~~
/in/foo.cc:30:12: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    if (ans >= (n - d))
        ~~~~^~~~~~~~~~
/in/foo.cc:39:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    else if ((n - c + n - d - 1) <= ans)
             ~~~~~~~~~~~~~~~~~~~~^~~~~~