submult.cpp: In function 'int main()': submult.cpp:43: warning: comparison between signed and unsigned integer expressions submult.cpp:45: warning: comparison between signed and unsigned integer expressions submult.cpp:34: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result submult.cpp:35: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result submult.cpp:38: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result submult.cpp:36: warning: 'a' may be used uninitialized in this function submult.cpp:36: warning: 'b' may be used uninitialized in this function