spion1.cpp: In function `void add(long int, long int)': spion1.cpp:29: warning: comparison between signed and unsigned integer expressions spion1.cpp: In function `int main()': spion1.cpp:63: warning: comparison between signed and unsigned integer expressions /tmp/ccEqoRkS.o(.text+0x278): In function `main': : the `gets' function is dangerous and should not be used.