#include <bits/stdc++.h>
#define MULTI int _; cin >> _; while(_--)
#define fi first
#define se second
#define pb(a) push_back(a)
#define rep(i, n) for(int i = 0; i < n; i++)
#define reps(i, n, m) for(int i = n; i <= m; i++)
#define repsv(i, n, m) for(int i = n; i >= m; i--)
#define vsz(a) (int)(a.size())
#define mp(a, b) make_pair(a, b)
#define all(a) a.begin(), a.end()

using namespace std;

typedef pair<double, double> pdd;
typedef pair<int, int> pii;
typedef vector<bool> vb;
typedef vector<int> vi;
typedef long long int ll;
typedef long double ld;
typedef vector<ll> vll;

#ifdef LOCAL
#include "debugs.hpp"
#else
#define dbg(...) 0
#endif

int n, m, k;

int score(int ed, int od){
    int ans = 0;
    if(ed == -1) return od+k;
    if(od == -1) return ed+k;
    reps(i, 0, k)
        ans = max(ans, min(ed+i, od+k-i));
    return ans;
}

void solve(){
    cin >> n >> m >> k;
    vector<vi> to(n);
    vi col(n);
    rep(i, n)
        cin >> col[i];
    rep(i, m){
        int a, b;
        cin >> a >> b;
        to[a-1].pb(b-1);
        to[b-1].pb(a-1);
    }
    int ans = 0;
    rep(s, n){
        vector<int> vu[2]; // vu[parity]
        vu[0]=vu[1]=vi(n, -1);
        int d = 0;
        vector<pii> tb {{s, 0}}; // (id, parity)
        while(!tb.empty()){
            vector<pii> ntb;
            while(!tb.empty()){
                pii curp = tb.back();
                tb.pop_back();
                int id = curp.fi;
                int parity = curp.se;
                if(vu[parity][id]!=-1)
                    continue;
                vu[parity][id] = d;
                for(int j : to[id])
                    ntb.push_back(mp(j, (col[id]==col[j] ? parity : parity^1)));
            }
            tb = ntb;
            d++;
        }
        rep(i, n)
            ans = max(ans, score(vu[0][i], vu[1][i]));
    }
    cout << ans << '\n';
}

int main(){
    ios_base::sync_with_stdio(false);
    // MULTI
    solve();
}