/* This problem corrspond to kind of Minimum-Cut staff Split a city into two node(I'd love to call it input-node and output-node). Connect them with a directed edge and the edge's capacity as the cost of the city A supper source node connect to the input-node of city S The output-node of city-D connect to the sink node Both edges above has an infinte capacity. Then sap. */#include <cstdio>#include <cstdlib>#include <iostream>#include <cstring>#include <string>#include <vector>#include <map>#include <algorithm>#include <cctype>#include <queue>#include <stack>#include <cmath>using namespace std;//STL#define MS(c, a) memset(c, a, sizeof c)//Syntax#define Rep(c, a, b) for (int c = (a); c < (b); c++)#define Nre(c, a, b) for (int c = (a); c > (b); c--)//DEBUG#define FK puts("Fu*k here!")//Typetypedef unsigned int UI;typedef long long LL;typedef long double LD;//Constantconst LL INFL = 0x7fffffffffffffffLL;const int INFI = 0x7fffffff;const int MAXN = 2005;const int MOD = 1000000007;//Arraytypedef int AI[MAXN];typedef bool AB[MAXN];typedef double AD[MAXN];typedef LL ALL[MAXN];typedef LD ALD[MAXN];//FSGstruct Edge{ int v, w, next;};vector<Edge> E;AI L;void G_ini(){E.clear(); MS(L, -1);}void AE(int u, int v, int w){Edge te = {v, w, L[u]};L[u] = E.size();E.push_back(te);}void SAE(int u, int v, int w){AE(u, v, w); AE(v, u, 0);}#define Ere(c, a, L) for (int c = L[a]; c != -1; c = E[c].next)//SAPint SAP(int src, int snk, int V){static AI dis, gap, _L, se;int u = src, mxf = 0, te = 0;memcpy(_L, L, sizeof L);MS(dis, -1); MS(gap, 0);gap[dis[snk] = 0] = 1;queue<int> Q; Q.push(snk);while (!Q.empty()){int u = Q.front(); Q.pop();Ere(i, u, L) if (E[i].w && dis[E[i].v] < 0){gap[dis[E[i].v] = dis[u] + 1]++; Q.push(E[i].v);}}while (dis[src] < V){for (int &i = _L[u]; i != -1; i = E[i].next)if (E[i].w && dis[u] == dis[E[i].v] + 1) break;if (_L[u] != -1){u = E[se[te++] = _L[u]].v;if (u == snk){int _i = 0, mf = INFI;Rep(i, 0, te) if (E[se[i]].w < mf){mf = E[se[i]].w; _i = i;}Rep(i, 0, te){E[se[i]].w -= mf; E[se[i] ^ 1].w += mf;}mxf += mf; te = _i;u = E[se[_i] ^ 1].v;}continue;}int md = V;Ere(i, u, L) if (E[i].w && dis[E[i].v] < md){md = dis[E[i].v]; _L[u] = i;}if (!--gap[dis[u]]) break;gap[dis[u] = md + 1]++;if (u != src) u = E[se[te-- - 1] ^ 1].v;}return mxf;}int n, m, s, d;int main(){while (~scanf("%d%d", &n, &m)){G_ini();scanf("%d%d", &s, &d);int V = 2 * n + 2, src = V - 2, snk = V - 1; s = (s - 1) << 1;d = (d - 1) << 1;SAE(src, s, INFI);SAE(d + 1, snk, INFI);Rep(i, 0, n){int w, u = i << 1;scanf("%d", &w);SAE(u, u + 1, w);}while (m--){int u, v;scanf("%d%d", &u, &v);u = (u - 1) << 1;v = (v - 1) << 1;SAE(u + 1, v, INFI);SAE(v + 1, u, INFI);}printf("%d\n", SAP(src, snk, V));}return 0;}
