#include <iostream>#include <string.h>#include <sstream>#include <stdio.h>#include <algorithm>#define F(i,a,b) for (int i=a;i<=b;i++)using namespace std;int n, cons;int a[21], alpha[21], pos[128], con[51][2];bool mk[21];void dfs(int x ){ if ( x == n + 1 ) { F(i,1,n) printf("%c", a[i] ); printf("n"); return ; } F(i,1,n) { if ( !mk[i] ) { a[x] = alpha[i]; pos[ a[x] ] = x ; mk[i] = true; bool ok = true; for (int j = 1; j<=cons && ok; j++) { int b = con[j][0], c = con[j][1]; if ( pos[b] == 0 || pos[c] == 0 || pos[b]<pos[c] ) ; else ok = false; } if (ok) dfs( x+1 ); pos[ a[x] ] = 0; mk[ i ] = false; } }}int main(){ string line; istringstream ss; char chra, chrb, chr; while (getline(cin, line) ) { memset(mk, 0, sizeof(mk) ); memset(pos, 0 ,sizeof(pos) ); n = 0, cons = 0; ss.clear(); ss.str( line ); while ( ss >> chr ) alpha[ ++n ] = chr ; sort(α[1], α[n+1]); getline(cin, line); ss.clear(); ss.str( line ); while (ss >> chra >> chrb ) { con[++cons][0] = chra; con[cons][1] = chrb; } dfs(1); printf("n"); } return 0;}
