/in/foo.cc: In function 'int main()':
/in/foo.cc:32:11: warning: 'x' may be used uninitialized in this function [-Wmaybe-uninitialized]
    x = (x + y) % MOD;
        ~~~^~~~
/in/foo.cc:24:9: warning: 'power' may be used uninitialized in this function [-Wmaybe-uninitialized]
   power *= b;
   ~~~~~~^~~~