benzina.cpp: In function 'int main()': benzina.cpp:58: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result benzina.cpp:59: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result benzina.cpp:61: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result benzina.cpp:64: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result benzina.cpp:109: warning: 'ca' may be used uninitialized in this function benzina.cpp:109: warning: 'cb' may be used uninitialized in this function benzina.cpp:109: warning: 'cc' may be used uninitialized in this function