Compilare: main.cpp: In function 'void read(long long int&)': main.cpp:18:39: warning: ignoring return value of 'size_t fread(void*, size_t, size_t, FILE*)', declared with attribute warn_unused_result [-Wunused-result] fread(buff, 1, dim, stdin), pos = 0; ^ main.cpp:22:39: warning: ignoring return value of 'size_t fread(void*, size_t, size_t, FILE*)', declared with attribute warn_unused_result [-Wunused-result] fread(buff, 1, dim, stdin), pos = 0; ^ main.cpp: In function 'int main()': main.cpp:32:35: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("zone.in", "r", stdin); ^ main.cpp:33:34: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("zone.out", "w", stdout); ^