sol.cpp:5:9: warning: unused variable 'x' [-Wunused-variable]
    int x = 0;
        ^
sol.cpp:7:14: warning: comparison of integers of different signedness: 'int' and 'unsigned int' [-Wsign-compare]
    if (a < b)
        ~ ^ ~
sol.cpp:12:5: warning: unused variable 'y' [-Wunused-variable]
    int y = 1;
        ^
3 warnings generated.
