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 MO = 998244353;

long solve(const(long) N, const(long) X) {
  long ans;
  if (X & 1) {
    ans = (N + 1) / 2;
  } else {
    const q = (N + 1) / (X + 3);
    const r = (N + 1) % (X + 3);
    ans += q * (X / 2 + 1);
    if (r < X) {
      ans += (r + 1) / 2;
    } else {
      ans += X / 2;
      if (X + 1 < r) {
        ans += 1;
      }
    }
    ans = N + 1 - ans;
  }
  return ans;
}

void main() {
  debug {{
    int calc(int n, int x) {
      if (x & 1) return n & 1;
      const r = n % (x + 3);
      if (r < x) return (r & 1);
      if (r == x + 1) return 0;
      return 1;
    }
    
    enum lim = 100;
    foreach (x; 1 .. lim) {
      auto dp = new bool[][][](lim, 2, 2);
      foreach (n; 0 .. lim) {
        foreach (s; 0 .. 2) foreach (t; 0 .. 2) {
          if (n >= 1) {
            if (!dp[n - 1][t][0]) dp[n][s][t] = true;
          }
          if (n >= x && !s) {
            if (!dp[n - x][t][1]) dp[n][s][t] = true;
          }
        }
      }
      foreach (n; 0 .. lim) {
        write(dp[n][0][0] ? '#' : '.');
      }
      writeln;
      foreach (n; 0 .. lim) {
        const res = calc(n, x);
        if (~res) {
          assert(dp[n][0][0] == cast(bool)(res), format("%s %s: %s %s", n, x, dp[n][0][0], res));
        }
        // assert(~res);
      }
    }
  }}
  
  debug {{
    enum lim = 20;
    foreach (x; 1 .. lim) if (!(x & 1)) {
      write(x, ":");
      foreach (n; 0 .. lim) {
        write(" ", solve(n, x));
      }
      writeln;
    }
  }}
  
  try {
    for (; ; ) {
      const numCases = readInt;
      foreach (caseId; 0 .. numCases) {
        const N = readLong;
        const X = readLong;
        
        const ans = solve(N, X);
        writeln(ans % MO);
      }
    }
  } catch (EOFException e) {
  }
}