template AND() {
    signal input a;
    signal input b;
    signal output c;

    c <== a*b;
}

template AND3() {
    signal input in1;
    signal input in2;
    signal input in3;
    signal output out;

    component and1 = AND();
    component and2 = AND();

    in1 ==> and1.a;
    in2 ==> and1.b;
    in3 ==> and2.a;
    and1.c ==> and2.b;
    and2.c ==> out;
}

template ToBin() {
    signal input in;
    signal output out[32];

    var lc = 0;

    for (var i=0; i<32; i++) {
        out[i] <-- (in >> i) & 1;
        lc = lc + out[i] * 2**i;
        out[i]*(out[i]-1) === 0;
    }

    lc === in;
}

component main = ToBin();