#include <iostream>
using namespace std;
class I
{
virtual int foo() = 0;
};
class A : I
{
int foo() override final {return 0;}
};
int main() {
// your code goes here
return 0;
}
I2luY2x1ZGUgPGlvc3RyZWFtPgp1c2luZyBuYW1lc3BhY2Ugc3RkOwoKY2xhc3MgSQp7Cgl2aXJ0dWFsIGludCBmb28oKSA9IDA7Cn07CgpjbGFzcyBBIDogSQp7CglpbnQgZm9vKCkgb3ZlcnJpZGUgZmluYWwge3JldHVybiAwO30KfTsKCmludCBtYWluKCkgewoJLy8geW91ciBjb2RlIGdvZXMgaGVyZQoJcmV0dXJuIDA7Cn0=