Compilare: main.cpp: In function 'int main()': main.cpp:22:45: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen ( "ciclueuler.in", "rt", stdin ); ^ main.cpp:24:35: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf ( " %d %d \n ", &n, &m ); ^ main.cpp:27:40: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf ( " %d %d \n ", &x, &y ); ^