let S = (x) => {
    return ++x;
}

let P = (x) =>{
    return --x;
}

let add = (a, b) => {
    if(b == 0) return a;
    if(b > 0) return add(S(a), P(b))
    return add(P(a), S(b))
}

let mul = (a, b) => {
    if(a == 0 || b == 0) return 0;
    if(b == 1) return a;
    if(b == -1) return -a;
    if(b > 1) return add(a, mul(a, P(b)));
    return add(mul(a, -1), mul(a, S(b)));
}

let pow = (a, b) => {
    if(a == 1) return 1;
    if(b < 0) return 0;
    if(b == 0) return 1;
    return mul(a, pow(a, P(b)))
}