grindina.cpp: In function 'int main()': grindina.cpp:70: warning: comparison between signed and unsigned integer expressions grindina.cpp:97: warning: comparison between signed and unsigned integer expressions grindina.cpp:101: warning: comparison between signed and unsigned integer expressions grindina.cpp:37: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result grindina.cpp:38: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result grindina.cpp:42: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result