x = [0,1,2,3,4,5,6,7,8,9]
n = int(input())
now = [0,0,0,0,0]
if n == 1:
    print("a")
elif n == 2:
    print("aa")
    print("ab")
elif n == 3:
    for a in range(3):
        for b in range(3):
            for c in range(3):
                y = [a,b,c]
                if sorted(set(y), key=y.index) == x[:len(set(y))]:
                    print("".join([chr(z+97) for z in y]))
                    if len(set(y)) == n:
                        exit()
elif n == 4:
    for a in range(n):
        for b in range(n):
            for c in range(n):
                for d in range(n):
                    y = [a,b,c,d]
                    if sorted(set(y), key=y.index) == x[:len(set(y))]:
                        print("".join([chr(z+97) for z in y]))
                        if len(set(y)) == n:
                            exit()
elif n == 5:
    for a in range(n):
        for b in range(n):
            for c in range(n):
                for d in range(n):
                    for e in range(n):
                        y = [a,b,c,d,e]
                        if sorted(set(y), key=y.index) == x[:len(set(y))]:
                            print("".join([chr(z+97) for z in y]))    
                            if len(set(y)) == n:
                                exit()   
                                         
elif n == 6:
    for a in range(n):
        for b in range(n):
            for c in range(n):
                for d in range(n):
                    for e in range(n):
                        for f in range(n):

                            y = [a,b,c,d,e,f]
                            if sorted(set(y), key=y.index) == x[:len(set(y))]:
                                print("".join([chr(z+97) for z in y]))          
                                if len(set(y)) == n:
                                    exit()          
elif n == 7:
    for a in range(n):
        for b in range(n):
            for c in range(n):
                for d in range(n):
                    for e in range(n):
                        for f in range(n):
                            for g in range(n):
                                y = [a,b,c,d,e,f,g]
                                if sorted(set(y), key=y.index) == x[:len(set(y))]:
                                    print("".join([chr(z+97) for z in y]))        
                                    if len(set(y)) == n:
                                        exit()            
elif n == 8:
    for a in range(n):
        for b in range(n):
            for c in range(n):
                for d in range(n):
                    for e in range(n):
                        for f in range(n):
                            for g in range(n):
                                for h in range(n):
                                    y = [a,b,c,d,e,f,g,h]
                                    if sorted(set(y), key=y.index) == x[:len(set(y))]:
                                        print("".join([chr(z+97) for z in y]))                  
                                        if len(set(y)) == n:
                                            exit()      
elif n == 9:
    for a in range(n):
        for b in range(n):
            for c in range(n):
                for d in range(n):
                    for e in range(n):
                        for f in range(n):
                            for g in range(n):
                                for h in range(n):
                                    for i in range(n):
                                        y = [a,b,c,d,e,f,g,h,i]
                                        if sorted(set(y), key=y.index) == x[:len(set(y))]:
                                            print("".join([chr(z+97) for z in y]))          
                                            if len(set(y)) == n:
                                                exit()         
elif n == 10:
    for a in range(n):
        for b in range(n):
            for c in range(n):
                for d in range(n):
                    for e in range(n):
                        for f in range(n):
                            for g in range(n):
                                for h in range(n):
                                    for i in range(n):
                                        for j in range(n):
                                            y = [a,b,c,d,e,f,g,h,i,j]
                                            if sorted(set(y), key=y.index) == x[:len(set(y))]:
                                                print("".join([chr(z+97) for z in y]))               
                                                if len(set(y)) == n:
                                                    exit()    
