public static void main(String[] args) {
InputStream inputStream = System.in;
OutputStream outputStream = System.out;
MyInputReader in = new MyInputReader(inputStream);
MyOutputWriter out = new MyOutputWriter(outputStream);
A solver = new A();
int testCount = Integer.parseInt(in.next());
for (int i = 1; i <= testCount; i++) solver.solve(i, in, out);
out.close();
}
public void solve(int testNumber, MyInputReader in, MyOutputWriter out) {
int A = in.nextInt();
int B = in.nextInt();
int M = in.nextInt();
int D = in.nextInt();
int d = gcd(A, B);
A /= d;
B /= d;
if (A % B == 0) {
out.printLine(0);
return;
}
HashMap<Integer, Integer> myMap = new HashMap<Integer, Integer>();
ArrayList<Integer> indexs = new ArrayList<Integer>();
A = A % B;
int index = 0;
int[] digit_count = new int[10];
Arrays.fill(digit_count, 0);
while (true) {
++index;
A = A * 10;
if (myMap.containsKey(A)) {
d = myMap.get(A);
int before = -2;
for (int i = 0; i < indexs.size(); i++) {
if (indexs.get(i) >= d) {
before = i - 1;
break;
}
}
if (before == -2) {
out.printLine(0);
return;
}
int loopLength = indexs.size() - before - 1;
if (loopLength == 0) {
out.printLine(0);
return;
}
M -= before + 1;
long actual_length = index - d;
int left = M % loopLength;
int divid = M / loopLength;
if (left == 0 && divid >= 1) {
divid -= 1;
left = loopLength - 1;
}
long ret = actual_length * divid + indexs.get(before + left + 1);
// out.printLine(loopLength + " " + actual_length + " " + left + " " + M + " " + before + "
// " + index);
out.printLine(ret);
return;
}
int t = A / B;
++digit_count[t];
if (digit_count[D] == M) {
out.printLine(index);
return;
}
if (t == D) {
indexs.add(index);
}
myMap.put(A, index);
A = A % B;
}
}