viteza.cpp: In function 'int main()': viteza.cpp:36: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result viteza.cpp:37: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result viteza.cpp:38: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result viteza.cpp:41: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result viteza.cpp:47: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result