furtuna.cpp: In function 'int main()': furtuna.cpp:72: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result furtuna.cpp:73: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result furtuna.cpp:74: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result furtuna.cpp:77: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result furtuna.cpp:86: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result furtuna.cpp:88: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result