func_code_string: #include <bits/stdc++.h>   using namespace std;   const int N = 450, inf = 1e8;   int n1, n2, m, r, b, node, s, t, S, T, a[N], id[N];   char col1[N], col2[N];   int head[N], ce = 1, inq[N], dis[N], maxflow, mincost, need;   struct edge {     int to, nxt, cap, flow, w;   } e[5000];   void lnk(int a, int b, int c, int w) {     e[++ce] = (edge){b, head[a], c, 0, w}, head[a] = ce;     e[++ce] = (edge){a, head[b], 0, 0, -w}, head[b] = ce;   }   bool bfs() {     for (int i = 1; i <= node; ++i) dis[i] = inf, inq[i] = 0;     dis[s] = 0, inq[s] = 1;     queue<int> q;     q.push(s);     while (!q.empty()) {       int u = q.front();       q.pop();       for (int i = head[u]; i; i = e[i].nxt) {         int v = e[i].to;         if (e[i].cap > e[i].flow && dis[v] > dis[u] + e[i].w) {           dis[v] = dis[u] + e[i].w;           if (!inq[v]) q.push(v), inq[v] = 1;         }       }       inq[u] = 0;     }     return dis[t] < inf;   }   int dfs(int u, int lim) {     if (u == t) return mincost += dis[t] * lim, lim;     int tag = 0;     inq[u] = 1;     for (int i = head[u]; i; i = e[i].nxt)       if (e[i].cap > e[i].flow && dis[e[i].to] == dis[u] + e[i].w &&           !inq[e[i].to]) {         int d = dfs(e[i].to, min(lim - tag, e[i].cap - e[i].flow));         tag += d, e[i].flow += d, e[i ^ 1].flow -= d;         if (tag == lim) {           inq[u] = 0;           return tag;         }       }     return tag;   }   int main() {     scanf( %d%d%d%d%d , &n1, &n2, &m, &r, &b);     scanf( %s , col1 + 1);     scanf( %s , col2 + 1);     node = n1 + n2, S = ++node, T = ++node, s = ++node, t = ++node;     for (int i = 1; i <= n1; ++i)       if (col1[i] ==  R )         ++a[i], --a[S], lnk(S, i, inf, 0);       else if (col1[i] ==  B )         --a[i], ++a[T], lnk(i, T, inf, 0);       else         lnk(S, i, inf, 0), lnk(i, T, inf, 0);     for (int i = 1; i <= n2; ++i)       if (col2[i] ==  R )         --a[i + n1], ++a[T], lnk(i + n1, T, inf, 0);       else if (col2[i] ==  B )         ++a[i + n1], --a[S], lnk(S, i + n1, inf, 0);       else         lnk(S, i + n1, inf, 0), lnk(i + n1, T, inf, 0);     for (int i = 1; i <= T; ++i)       if (a[i] > 0)         lnk(s, i, a[i], 0), need += a[i];       else if (a[i] < 0)         lnk(i, t, -a[i], 0);     lnk(T, S, inf, 0);     for (int i = 1, u, v; i <= m; ++i)       scanf( %d%d , &u, &v), id[i] = ce + 1, lnk(u, v + n1, 1, r),                              lnk(v + n1, u, 1, b);     while (bfs()) maxflow += dfs(s, inf);     if (maxflow < need) {       puts( -1 );       return 0;     }     printf( %d n , mincost);     for (int i = 1; i <= m; ++i)       if (e[id[i]].flow)         putchar( R );       else if (e[id[i] + 2].flow)         putchar( B );       else         putchar( U );     return 0;   }   