import std.conv, std.functional, std.range, std.stdio, std.string;
import std.algorithm, std.array, std.bigint, std.bitmanip, std.complex, std.container, std.math, std.mathspecial, std.numeric, std.regex, std.typecons;
import core.bitop;

class EOFException : Throwable { this() { super("EOF"); } }
string[] tokens;
string readToken() { for (; tokens.empty; ) { if (stdin.eof) { throw new EOFException; } tokens = readln.split; } auto token = tokens.front; tokens.popFront; return token; }
int readInt() { return readToken.to!int; }
long readLong() { return readToken.to!long; }
real readReal() { return readToken.to!real; }

bool chmin(T)(ref T t, in T f) { if (t > f) { t = f; return true; } else { return false; } }
bool chmax(T)(ref T t, in T f) { if (t < f) { t = f; return true; } else { return false; } }

int binarySearch(alias pred, T)(in T[] as) { int lo = -1, hi = cast(int)(as.length); for (; lo + 1 < hi; ) { const mid = (lo + hi) >> 1; (unaryFun!pred(as[mid]) ? hi : lo) = mid; } return hi; }
int lowerBound(T)(in T[] as, T val) { return as.binarySearch!(a => (a >= val)); }
int upperBound(T)(in T[] as, T val) { return as.binarySearch!(a => (a > val)); }


enum INF = 10L^^18;

long solve(const(long) X, const(long) Y, const(long) A) {
  alias Entry = Tuple!(long, "z", long, "c");
  Entry[] es, fs;
  {
    long x = X;
    long c;
    for (; ; ) {
      es ~= Entry(x, c);
      if (x == 0) {
        break;
      }
      x /= A;
      c += 1;
    }
  }
  {
    long y0 = Y, y1 = Y;
    long c0, c1;
    long cost;
    for (; ; ) {
      fs ~= Entry(y0, c0);
      fs ~= Entry(y1, c1);
      if (y0 == 0 && y1 <= 1) {
        break;
      }
      long cc0 = INF, cc1 = INF;
      {
        const r = y0 % A;
        const s = r ? (A - r) : 0;
        chmin(cc0, c0 + r + 1);
        chmin(cc1, c0 + s + 1);
      }
      {
        const r = y1 % A;
        const s = r ? (A - r) : 0;
        chmin(cc0, c1 + r + 1);
        chmin(cc1, c1 + s + 1);
      }
      y0 = y0 / A;
      y1 = (y1 + A - 1) / A;
      c0 = cc0;
      c1 = cc1;
    }
  }
  debug {
    writeln("es = ", es);
    writeln("fs = ", fs);
  }
  
  long ans = INF;
  foreach (e; es) foreach (f; fs) {
    chmin(ans, e.c + abs(e.z - f.z) + f.c);
  }
  return ans;
}

void main() {
  try {
    for (; ; ) {
      const numCases = readInt;
      foreach (caseId; 0 .. numCases) {
        const X = readLong;
        const Y = readLong;
        const A = readLong;
        
        const ans = solve(X, Y, A);
        writeln(ans);
      }
    }
  } catch (EOFException e) {
  }
}