palind.cpp: In function 'void f(int)': palind.cpp:11: warning: unused variable 'x' palind.cpp: In function 'void solve()': palind.cpp:43: warning: unused variable 'val' palind.cpp:45: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result palind.cpp:47: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result palind.cpp: In function 'int main()': palind.cpp:55: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result palind.cpp:56: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result palind.cpp:58: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result