the scope and priority of variable in c++

Question

Could anybody explains to me why the result is 2, which x is using and why.

auto x = 0;

int f(int i){
    auto x = 1;
    {
        static auto x = 0;
        x += i;
    }
    return x;
}
int main() {
    cout << f(1) + f(2) <<endl;// result 2
    return 0;
}

Answer 1

The inner x shadows the outer one, but the mutations only apply to the inner most scope

int f(int i){
    auto x = 1;              // consider this "x1"
    {
        static auto x = 0;   // this is "x2"
        x += i;              // mutates "x2" but not "x1"
    }
    return x;                // return "x1" which is still 1
}

Therefore

f(1) + f(2)                  // 1 + 1 == 2