import core.bitop, std.algorithm, std.ascii, std.bigint, std.conv,
    std.functional, std.math, std.numeric, std.range, std.stdio, std.string,
    std.random, std.typecons, std.container;

ulong MAX = 100_100, MOD = 1_000_000_007, INF = 1_000_000_000_000;
alias sread = () => readln.chomp();
alias lread(T = long) = () => readln.chomp.to!(T);
alias aryread(T = long) = () => readln.split.to!(T[]);
alias Pair = Tuple!(long, "x", long, "y");
alias PQueue(T, alias less = "a>b") = BinaryHeap!(Array!T, less);

void main()
{
    long n, m;
    scan(n, m);
    auto t = new long[](n + 1);
    foreach (i; iota(m))
    {
        long x, y, z;
        scan(x, y, z);
        if (x > y)
            swap(x, y);
        long root(long x)
        {
            if (t[x] == 0)
                return x;
            else
                return root(t[x]);
        }

        t[y] = x;
    }
    writeln(t.filter!(x => x == 0).array().length - 1);
}

void scan(TList...)(ref TList Args)
{
    auto line = readln.split();
    foreach (i, T; TList)
    {
        T val = line[i].to!(T);
        Args[i] = val;
    }
}
