sir6.cpp: In function 'int main()': sir6.cpp:7: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result sir6.cpp:8: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result sir6.cpp:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result sir6.cpp:12: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result sir6.cpp:33: warning: assuming signed overflow does not occur when assuming that (X + c) < X is always false