/in/ex3.cpp: In function 'std::__cxx11::string get_and_removespace()':
/in/ex3.cpp:58:23: error: comparison between signed and unsigned integer expressions [-Werror=sign-compare]
     for (int i = 0; i < size(str); i++)
                     ~~^~~~~~~~~~~
/in/ex3.cpp:65:23: error: comparison between signed and unsigned integer expressions [-Werror=sign-compare]
     for (int i = 0; i < size(str); i++)
                     ~~^~~~~~~~~~~
/in/ex3.cpp: In function 'void encryptC()':
/in/ex3.cpp:78:23: error: comparison between signed and unsigned integer expressions [-Werror=sign-compare]
     for (int i = 0; i < size(str); i++)
                     ~~^~~~~~~~~~~
/in/ex3.cpp: In function 'void encryptS()':
/in/ex3.cpp:89:23: error: comparison between signed and unsigned integer expressions [-Werror=sign-compare]
     for (int i = 0; i < size(str); i++)
                     ~~^~~~~~~~~~~
/in/ex3.cpp: In function 'void decryptC()':
/in/ex3.cpp:100:23: error: comparison between signed and unsigned integer expressions [-Werror=sign-compare]
     for (int i = 0; i < size(str); i += 3)
                     ~~^~~~~~~~~~~
/in/ex3.cpp: In function 'void decryptS()':
/in/ex3.cpp:108:23: error: comparison between signed and unsigned integer expressions [-Werror=sign-compare]
     for (int i = 0; i < size(str); i += 4)
                     ~~^~~~~~~~~~~
cc1plus: all warnings being treated as errors
/in/compile/Makefile:20: recipe for target 'ex3.o' failed
make: *** [ex3.o] Error 1