function main(input) {
  let [N, K] = getIntegers(input, " ");
  let dp = new Array(10e5).fill(0);
  let A = input.shift().split(" ").map(function(e) {
    let n = Number(e);
    dp[n]++;
    return n;
  });
  
  let count = 0;
  for(let i=0; i<N; i++) {
    let V = K - A[i];
    count = count +  (V >= 0 ? dp[V] : 0);
  }
  console.log(count);
}

//-- functions ------------------------------------

function getIntegers(lines, sep) {
  if(sep === undefined) {
    return lines.map(function(e) {
      return Number(e);
    });  
  } else {
    return lines.shift().split(sep).map(function(e) {
      return Number(e);
    });  
  }
}

function getBigIntegers(lines, sep=" ") {
  return lines.shift().split(sep).map(function(e) {
    return BigInt(e);
  });
}

function getStrings(lines, sep=" ") {
  return lines.shift().split(sep);
}

function twoDimenArrayByValue(h, w, value) {
  const list = new Array(h);
  for(let i=0; i<h; i++) {
    list[i] = new Array(w).fill().map(function(e) {
      return value.constructor == Array ? Array.from(value) : value;
    });
  }
  return list;
}

function twoDimenArrayByStrings(h, strings) {
  const list = new Array(h);
  for(let i=0; i<h; i++) {
    list[i] = strings.shift().split("");
  }
  return list;
}

function distance(x1, y1, x2, y2) {
  return Math.sqrt((x2-x1) * (x2-x1) + (y2-y1) * (y2-y1));
}

function gcd(a, b) {
  return b === 0 ? a : gcd(b, a % b);
}

const lower_bound = (arr, val, first = 0, last = arr.length) => {
    first -= 1; // 一番端の位置からさらにずらす
    while (last - first > 1) {
        const mid = first + Math.floor((last - first) / 2);
        if (arr[mid] < val)
            first = mid;
        else
            last = mid;
    }
    return last;
}

const upper_bound = (arr, val, first = 0, last = arr.length) => {
    first -= 1;
    while (last - first > 1) {
        const mid = first - Math.floor((last - first) / 2);
        if (arr[mid] <= val) // ココを直すだけ
            first = mid;
        else
            last = mid;
    }
    return last;
}

//-- Array -------------------------------------------

Array.prototype.deepCopy = function(list) {
  let retList = [];
  for(let i=0; i<list.length; i++) {
    retList[i] = list[i].constructor == Array ? Array.from(list[i]) : list[i];
  }
  return retList;
};

Array.prototype.out = function() {
  let outList = [];
  if(this[0].constructor == Array) {
    for(let i=0; i<this.length; i++) {
      outList.push(this[i].join(" "));
    } 
  } else {
    outList.push(this.join(" "));
  }
  console.log(outList.join("\n"));
};

Array.prototype.pushNoSameValue = function(...values) {
  values.forEach(function(e) {
    if(!this.includes(e)) {
      this.push(e);
    }
  }, this);
};

Array.prototype.sortByIntegers = function() {
  this.sort(function(a, b) {
    return a - b;
  });
};

main(require("fs").readFileSync("/dev/stdin", "utf8").trim().split("\n"));