stiva.cpp: In function 'int main()': stiva.cpp:11: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result stiva.cpp:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result stiva.cpp:14: warning: ignoring return value of 'char* gets(char*)', declared with attribute warn_unused_result /tmp/ccRBQ3ln.o: In function `main': stiva.cpp:(.text+0x5b): warning: the `gets' function is dangerous and should not be used.