adevar.cpp: In function 'int main()': adevar.cpp:63: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result adevar.cpp:64: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result adevar.cpp:71: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result adevar.cpp:79: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result