insule.cpp: In function 'int main()': insule.cpp:40: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result insule.cpp:41: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result insule.cpp:42: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result insule.cpp:45: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result insule.cpp:49: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result