joc15.cpp: In function 'int main()': joc15.cpp:8: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result joc15.cpp:9: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result joc15.cpp:11: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result joc15.cpp:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result joc15.cpp:18: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result