asmax.cpp: In function 'int rec(int)': asmax.cpp:11: warning: comparison between signed and unsigned integer expressions asmax.cpp:22: warning: comparison between signed and unsigned integer expressions asmax.cpp: In function 'int main()': asmax.cpp:33: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result asmax.cpp:34: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result asmax.cpp:35: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result asmax.cpp:39: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result asmax.cpp:49: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result