/+ dub.sdl:
    name "D"
    dependency "dcomp" version=">=0.7.4"
+/

import std.stdio, std.algorithm, std.range, std.conv;
// import dcomp.foundation, dcomp.scanner;

// import dcomp.datastructure.unionfind;

int main() {
    Scanner sc = new Scanner(stdin);

    int n, m, k;
    sc.read(n, m, k);
    int[] col;
    sc.read(col);
    int zc = col.count(0).to!int;
    struct E {int from, to; long dist; }
    E[] edges;
    foreach (i; 0..n) {
        if (col[i]) edges ~= E(i, n+col[i]-1, 0);
    }
    foreach (i; 0..m) {
        int a, b; long w;
        sc.read(a, b, w);
        a--; b--;
        edges ~= E(a, b, w);
    }
    edges.sort!"a.dist<b.dist";
    auto uf = UnionFind(n+k);
    long sm = 0;
    foreach (e; edges) {
        if (uf.count <= zc+1) break;
        int a = e.from, b = e.to;
        long c = e.dist;
        if (uf.same(a, b)) continue;
        uf.merge(a, b);
        sm += c;
    }
    if (uf.count > zc+1) sm = -1;
    writeln(sm);
    return 0;
}
/* IMPORT /home/yosupo/Program/dcomp/source/dcomp/datastructure/unionfind.d */
// module dcomp.datastructure.unionfind;

 
struct UnionFind {
    import std.algorithm : map, swap, each;
    import std.range : iota, array;
    import std.conv : to;
    int[] id;  
    int[][] groups;  
    int count;  
     
    this(size_t n) {
        id = iota(n.to!int).array;
        groups = iota(n.to!int).map!(a => [a]).array;
        count = n.to!int;
    }
     
    void merge(size_t a, size_t b) {
        if (same(a, b)) return;
        count--;
        int x = id[a], y = id[b];
        if (groups[x].length < groups[y].length) swap(x, y);
        groups[y].each!(a => id[a] = x);
        groups[x] ~= groups[y];
        groups[y] = [];
    }
     
    int[] group(size_t i) {
        return groups[id[i]];
    }
     
    bool same(size_t a, size_t b) {
        return id[a] == id[b];
    }
}

 
 

 
/* IMPORT /home/yosupo/Program/dcomp/source/dcomp/foundation.d */
// module dcomp.foundation;
 
static if (__VERSION__ <= 2070) {
    /*
    Copied by https://github.com/dlang/phobos/blob/master/std/algorithm/iteration.d
    Copyright: Andrei Alexandrescu 2008-.
    License: $(HTTP boost.org/LICENSE_1_0.txt, Boost License 1.0).
    */
    template fold(fun...) if (fun.length >= 1) {
        auto fold(R, S...)(R r, S seed) {
            import std.algorithm : reduce;
            static if (S.length < 2) {
                return reduce!fun(seed, r);
            } else {
                import std.typecons : tuple;
                return reduce!fun(tuple(seed), r);
            }
        }
    }
     
}

import core.bitop : popcnt;
static if (!__traits(compiles, popcnt(ulong.max))) {
    public import core.bitop : popcnt;
    int popcnt(ulong v) {
        return popcnt(cast(uint)(v)) + popcnt(cast(uint)(v>>32));
    }
}

bool poppar(ulong v) {
    v^=v>>1;
    v^=v>>2;
    v&=0x1111111111111111UL;
    v*=0x1111111111111111UL;
    return ((v>>60) & 1) != 0;
}
/* IMPORT /home/yosupo/Program/dcomp/source/dcomp/scanner.d */
// module dcomp.scanner;

// import dcomp.array;

 
class Scanner {
    import std.stdio : File;
    import std.conv : to;
    import std.range : front, popFront, array, ElementType;
    import std.array : split;
    import std.traits : isSomeChar, isStaticArray, isArray; 
    import std.algorithm : map;
    File f;
    this(File f) {
        this.f = f;
    }
    char[512] lineBuf;
    char[] line;
    private bool succW() {
        import std.range.primitives : empty, front, popFront;
        import std.ascii : isWhite;
        while (!line.empty && line.front.isWhite) {
            line.popFront;
        }
        return !line.empty;
    }
    private bool succ() {
        import std.range.primitives : empty, front, popFront;
        import std.ascii : isWhite;
        while (true) {
            while (!line.empty && line.front.isWhite) {
                line.popFront;
            }
            if (!line.empty) break;
            line = lineBuf[];
            f.readln(line);
            if (!line.length) return false;
        }
        return true;
    }

    private bool readSingle(T)(ref T x) {
        import std.algorithm : findSplitBefore;
        import std.string : strip;
        import std.conv : parse;
        if (!succ()) return false;
        static if (isArray!T) {
            alias E = ElementType!T;
            static if (isSomeChar!E) {
                 
                 
                auto r = line.findSplitBefore(" ");
                x = r[0].strip.dup;
                line = r[1];
            } else static if (isStaticArray!T) {
                foreach (i; 0..T.length) {
                    bool f = succW();
                    assert(f);
                    x[i] = line.parse!E;
                }
            } else {
                FastAppender!(E[]) buf;
                while (succW()) {
                    buf ~= line.parse!E;
                }
                x = buf.data;
            }
        } else {
            x = line.parse!T;
        }
        return true;
    }
    int read(T, Args...)(ref T x, auto ref Args args) {
        if (!readSingle(x)) return 0;
        static if (args.length == 0) {
            return 1;
        } else {
            return 1 + read(args);
        }
    }
}


 
 

 
/* IMPORT /home/yosupo/Program/dcomp/source/dcomp/array.d */
// module dcomp.array;

 
T[N] fixed(T, size_t N)(T[N] a) {return a;}

 
 

 
struct FastAppender(A, size_t MIN = 4) {
    import std.algorithm : max;
    import std.conv;
    import std.range.primitives : ElementEncodingType;
    import core.stdc.string : memcpy;

    private alias T = ElementEncodingType!A;
    private T* _data;
    private uint len, cap;
     
    @property size_t length() const {return len;}
    bool empty() const { return len == 0; }
     
    void reserve(size_t nlen) {
        import core.memory : GC;
        if (nlen <= cap) return;
        
        void* nx = GC.malloc(nlen * T.sizeof);

        cap = nlen.to!uint;
        if (len) memcpy(nx, _data, len * T.sizeof);
        _data = cast(T*)(nx);
    }
    void free() {
        import core.memory : GC;
        GC.free(_data);
    }
     
    void opOpAssign(string op : "~")(T item) {
        if (len == cap) {
            reserve(max(MIN, cap*2));
        }
        _data[len++] = item;
    }
     
    void insertBack(T item) {
        this ~= item;
    }
     
    void removeBack() {
        len--;
    }
     
    void clear() {
        len = 0;
    }
    ref inout(T) back() inout { assert(len); return _data[len-1]; }
    ref inout(T) opIndex(size_t i) inout { return _data[i]; }
     
    T[] data() {
        return (_data) ? _data[0..len] : null;
    }
}

 
 

/*
This source code generated by dcomp and include dcomp's source code.
dcomp's Copyright: Copyright (c) 2016- Kohei Morita. (https://github.com/yosupo06/dcomp)
dcomp's License: MIT License(https://github.com/yosupo06/dcomp/blob/master/LICENSE.txt)
*/


Measured memory_bytes: 23596