circular.cpp: In function 'int main()': circular.cpp:24: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result circular.cpp:25: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result circular.cpp:29: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result circular.cpp:31: warning: ignoring return value of 'char* gets(char*)', declared with attribute warn_unused_result circular.cpp:32: warning: ignoring return value of 'char* gets(char*)', declared with attribute warn_unused_result /tmp/ccu7xWY9.o: In function `main': circular.cpp:(.text+0xea): warning: the `gets' function is dangerous and should not be used.