siruri2.cpp: In function 'int main()': siruri2.cpp:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result siruri2.cpp:11: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result siruri2.cpp:13: warning: ignoring return value of 'char* gets(char*)', declared with attribute warn_unused_result siruri2.cpp:15: warning: ignoring return value of 'char* gets(char*)', declared with attribute warn_unused_result /tmp/ccbnXKIP.o: In function `main': siruri2.cpp:(.text+0x60): warning: the `gets' function is dangerous and should not be used.