#include <iostream>
#include <stdio.h>
#include <string.h>
using namespace std;
int n,m;
char prefix;
char suffix;
int**graph;
int* arrLen;
int* inDegree;
int* inDegree_bak;
bool* flag;
char* str;
int IsAcyclic(char* str);
int IsAcyclic(char* str) {
    int strLen = 0;
    int visited = 0;
    int cc = 0;
    int r = 0;
    bool updated = false;
    for(int i=0;i<n;i++) {
        if(inDegree[i]==0) {
            cc++;
        }
    }
    while(visited<n) {
        updated = false;
        for(int i=0;i<n;i++) {
            if(!flag[i]&&inDegree[i]==0) {
                if(cc!=1) {
                    r = 1;
                }
                str[strLen++] = i+'A';
                str[strLen] = '\0';
                cc--;
                visited ++;
                updated = true;
                flag[i] = true;
                int len = arrLen[i];
                for(int j=0;j<len;j++) {
                    if((--inDegree[graph[i][j]])==0)
                        cc++;
                }
            }
        }
        if(!updated)
            return 0;//incomsisitency
    }
    if(r==0) {
        return 2;//determined
    }else
        return 1;//undetermined
}
int main()
{
    str = new char[27];
    bool isFirstRound = true;
    while(1) {
        scanf("%d%d",&n,&m);
        fflush(stdin);
        if(!isFirstRound) {
            for(int i=0;i<n;i++) {
                delete graph[i];
            }
            delete graph;
            delete arrLen;
            delete inDegree;
            delete flag;
            delete inDegree_bak;
            isFirstRound = false;
        }
        if(n==0&&m==0)
            break;
        graph = new int*[n];
        arrLen = new int[n];
        inDegree = new int[n];
        inDegree_bak = new int[n];
        flag = new bool[n];
        memset(flag,0,sizeof(bool)*n);
        memset(inDegree,0,sizeof(int)*n);
        memset(inDegree_bak,0,sizeof(int)*n);
        memset(arrLen,0,sizeof(int)*n);
        for(int i=0;i<n;i++) {
            graph[i] = new int[26];
            memset(graph[i],0,sizeof(int)*26);
        }
        int temp = 0;
        int endRound = 0;
        for(int i=0;i<m;i++) {
            scanf("%c<%c",&prefix,&suffix);
            fflush(stdin);
            if(endRound==1)
                continue;
            //Add A node;
            int f = prefix-'A';
            int b = suffix-'A';
            graph[f][arrLen[f]++] = b;
            inDegree_bak[b]++;
            memcpy(inDegree,inDegree_bak,sizeof(int)*n);
            memset(flag,0,sizeof(bool)*n);
            temp = IsAcyclic(str);
            if(temp==0) {
                printf("Inconsistency found after %d relations.\n",i+1);
                endRound = 1;
            }else if(temp==2) {
                printf("Sorted sequence determined after %d relations: %s.\n",i+1,str);
                endRound = 1;
            }
        }
        if(temp==1) {
            printf("Sorted sequence cannot be determined.\n");
        }
    }
    return 0;
}