import sys
readline=sys.stdin.readline

def Hirschberg_Algorithm(N,lst,S,bit_set=False):
    partial_sum=[0]*(N+1)
    partial_sum[0]=0
    partial_sum[N]=S
    stack=[(0,N)]
    while stack:
        l,r=stack.pop()
        mid=(l+r)//2
        s=partial_sum[r]-partial_sum[l]
        if bit_set:
            dpL=Bit_Set(1,element_range=s+1)
        else:
            dpL=1
        for i in range(l,mid):
            dpL|=dpL<<lst[i]
            if not bit_set:
                dpL&=(1<<s+1)-1
        if bit_set:
            dpR=Bit_Set(1<<s,element_range=s+1)
        else:
            dpR=1<<s
        for i in range(mid,r):
            dpR|=dpR>>lst[i]
        dp=dpL&dpR
        if bit_set and not dp.bit_set or not bit_set and dp==0:
            return None
        partial_sum[mid]=partial_sum[l]+(dp.Find_First() if bit_set else (dp&-dp).bit_length()-1)
        if mid-l>=2:
            stack.append((l,mid))
        if r-mid>=2:
            stack.append((mid,r))
    return partial_sum

N,X=map(int,readline().split())
A=list(map(int,readline().split()))
M=10**5
idx0=[]
idx1=[]
for i in range(N):
    if A[i]>=M:
        idx0.append(i)
    else:
        idx1.append(i)
le0=len(idx0)
le1=len(idx1)
dp=1
for i in range(1,le1+1):
    dp|=dp<<A[idx1[i-1]]
for bit in range(1<<le0):
    s=sum(A[idx0[i]] for i in range(le0) if bit&1<<i)
    if X-s>=0 and dp&1<<X-s:
        ans_lst=[None]*N
        for i in range(le0):
            if bit&1<<i:
                ans_lst[idx0[i]]="o"
            else:
                ans_lst[idx0[i]]="x"
        cumsum_A=Hirschberg_Algorithm(le1,[A[i] for i in idx1],X-s)
        for i in range(le1):
            if cumsum_A[i]<cumsum_A[i+1]:
                ans_lst[idx1[i]]="o"
            else:
                ans_lst[idx1[i]]="x"
        print(*ans_lst,sep="")
        break
else:
    print("No")