import std.experimental.all;

T read(T)() { return readln.chomp.to!T; }
T[] reads(T)() { return readln.split.to!(T[]); }
alias readint = read!int;
alias readints = reads!int;

long calc(int x, int[] a) {
    auto freq = new int[](a.maxElement + 1);
    foreach (e; a)
        freq[e]++;

    long ans = 0;
    foreach (e; a) {
        int y = x - e;
        if (0 <= y && y < freq.length)
            ans += freq[y];
    }
    return ans;
}

void main() {
    auto nx = readints;
    int x = nx[1];
    auto a = readints;
    writeln(calc(x, a));
}