#include <iostream>
#include <cstdio>
#include <cstring>
#include <vector>
#include <map>
#include <string>
#include <utility>
#include <algorithm>
using namespace std;const int N = 10;struct node {int num, index;node *pre, *next[4];void init() {num = index = 0;pre = 0;memset(next, 0, sizeof(next));}
};int n, l, cnt, val[10], sval[1<<N];
bool dp[2][N*150][1<<N];
char str[150];map <char, int> h;
node trie[N*150];
node *root, *queue[N*150];void insertStr(node *root, char *str, int pos) {int lab, len = strlen(str);for(int i = 0; i < len; i++) {lab = h[str[i]];if(root->next[lab] == NULL) {root->next[lab] = &trie[++cnt];root->next[lab]->init();root->next[lab]->index = cnt;}root = root->next[lab];}root->num |= (1<<pos);
}void buildAC() {int head, tail;node *u;root->pre = root;head = tail = 0;queue[0] = root;while(head <= tail) {u = queue[head++];u->num |= u->pre->num;for(int i = 0; i < 4; i++) {if(u->next[i] == 0) {if(u == root)  u->next[i] = root;else  u->next[i] = u->pre->next[i];}else {if(u == root)  u->next[i]->pre = root;else  u->next[i]->pre = u->pre->next[i];queue[++tail] = u->next[i];}}}
}int main() {//freopen("data.in", "r", stdin);h['A'] = 0; h['G'] = 1; h['T'] = 2; h['C'] = 3;while(scanf("%d%d", &n, &l) != EOF) {memset(trie, 0, sizeof(trie));root = &trie[0];root->init();cnt = 0;for(int i = 0; i < n; i++) {scanf(" %s%d", str, &val[i]);insertStr(root, str, i);}memset(sval, 0, sizeof(sval));for(int state = 0; state < (1<<n); state++) {for(int j = 0; j < n; j++)if(state&(1<<j))sval[state] += val[j];}buildAC();memset(dp, false, sizeof(dp));int u, v;u = 0;dp[u][0][0] = true;for(int i = 0; i < l; i++) {v = u^1;memset(dp[v], false, sizeof(dp[v]));for(int j = 0; j <= cnt; j++)for(int k = 0; k < (1<<n); k++) {if(!dp[u][j][k])  continue;else {for(int p = 0; p < 4; p++) {int dindex = trie[j].next[p]->index;dp[v][dindex][k|trie[dindex].num] = true;}}}u = v;}int ans = -1;for(int i = 0; i <= cnt; i++)for(int j = 0; j < (1<<n); j++) {if(dp[u][i][j] == false)  continue;ans = max(ans, sval[j]);}if(ans != -1)  printf("%d\n", ans);else  printf("No Rabbit after 2012!\n");}return  0;
}