Compilare: main.cpp: In function 'int Z(int, int)': main.cpp:3:114: warning: no return statement in function returning non-void [-Wreturn-type] main.cpp: In function 'int main()': main.cpp:5:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] main.cpp:4:31: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] main.cpp:4:67: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]