bal.cpp: In function 'int main()': bal.cpp:4: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result bal.cpp:5: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result bal.cpp:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result bal.cpp:9: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result bal.cpp:16: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result