func_code_string: #include <bits/stdc++.h>   using namespace std;   struct Edge {     long long to, dis, next, cost;   } edge[24050];   long long num = -1;   bool vis[10010];   long long mincost;   long long pre[10010], head[10010], cost[10010], last[10010], flow[10010], n, k,       a[110], b[110], s, t, maxflow;   long long to[110];   void add(long long f, long long t, long long dis, long long cost) {     edge[++num].to = t;     edge[num].dis = dis;     edge[num].next = head[f];     edge[num].cost = cost;     head[f] = num;     edge[++num].to = f;     edge[num].dis = 0;     edge[num].cost = -cost;     edge[num].next = head[t];     head[t] = num;   }   queue<long long> q;   bool spfa(long long s, long long t) {     memset(cost, 0x3f3f3f3f, sizeof cost);     memset(flow, 0x3f3f3f3f, sizeof flow);     memset(vis, 0, sizeof vis);     q.push(s);     vis[s] = 1;     cost[s] = 0;     pre[t] = -1;     while (!q.empty()) {       long long nowp = q.front();       q.pop();       vis[nowp] = 0;       for (long long i = head[nowp]; i != -1; i = edge[i].next) {         if (edge[i].dis > 0 && cost[edge[i].to] > cost[nowp] + edge[i].cost) {           cost[edge[i].to] = cost[nowp] + edge[i].cost;           pre[edge[i].to] = nowp;           last[edge[i].to] = i;           flow[edge[i].to] = min(flow[nowp], edge[i].dis);           if (!vis[edge[i].to]) {             vis[edge[i].to] = 1;             q.push(edge[i].to);           }         }       }     }     return pre[t] != -1;   }   void MCMF(long long s, long long t) {     while (spfa(s, t)) {       long long now = t;       maxflow += flow[t];       mincost += flow[t] * cost[t];       while (now != s) {         edge[last[now]].dis -= flow[t];         edge[last[now] ^ 1].dis += flow[t];         now = pre[now];       }     }   }   signed main() {     long long T;     cin >> T;     while (T--) {       num = -1;       memset(to, -1, sizeof to);       memset(head, -1, sizeof head);       cin >> n >> k;       for (long long i = 1; i <= n; i++) cin >> a[i] >> b[i];       maxflow = mincost = 0;       s = 0;       t = 2 * n + 1;       for (long long i = 1; i <= n; i++) add(s, i, 1, 0), add(i + n, t, 1, 0);       for (long long i = 1; i <= n; i++) {         for (long long j = 1; j <= n; j++) {           long long nc = 0;           if (j <= k - 1)             nc = a[i] + b[i] * (j - 1ll);           else if (j != n)             nc = b[i] * (k - 1ll);           else             nc = a[i] + b[i] * (k - 1ll);           nc = 0x3f3f3f3f - nc;           add(i, j + n, 1, nc);         }       }       MCMF(s, t);       long long nowi = -1;       for (long long i = n * 4; i <= num; i += 2) {         nowi++;         if (edge[i].dis == 0) to[1 + nowi % n] = 1 + nowi / n;       }       cout << 2 * n - k << endl;       for (long long i = 1; i <= k - 1; i++) cout << to[i] <<    ;       for (long long i = k; i < n; i++) cout << to[i] <<     << -to[i] <<    ;       cout << to[n];       cout << endl;     }     return 0;   }   