circular.cpp: In function 'int main()': circular.cpp:22: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result circular.cpp:23: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result circular.cpp:26: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result circular.cpp:28: 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/cc2rjkFY.o: In function `main': circular.cpp:(.text+0x107): warning: the `gets' function is dangerous and should not be used.