import.cpp: In function 'void dfs(int, int)': import.cpp:40: warning: comparison between signed and unsigned integer expressions import.cpp: In function 'int main()': import.cpp:52: warning: unused variable 'j' import.cpp:49: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result import.cpp:50: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result import.cpp:51: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result import.cpp:55: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result import.cpp:63: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result