#include<stdio.h>
#include<stdlib.h>
#include<string.h>

typedef long long int int64;

#define MAX(a,b) ((a)>(b)?(a):(b))
#define MIN(a,b) ((a)<(b)?(a):(b))
#define ABS(a) ((a)>(0)?(a):-(a))

#define POS(i,j) ((i)*(100*blen+1)+(j))

void run(void){
  int n;
  int64 x;
  scanf("%d%lld",&n,&x);
  int a[100];
  int i,j;
  for(i=0;i<n;i++) scanf("%d",a+i);
  int b[100],c[10];
  int blen=0;
  int clen=0;
  for(i=0;i<n;i++){
    if(a[i]<=100){
      b[blen++]=i;
    } else {
      c[clen++]=i;
    }
  }
  char *dp=(char *)calloc((blen+1)*(100*blen+1),sizeof(char));
  dp[POS(0,0)]=1;
  for(i=0;i<blen;i++){
    memcpy(dp+POS(i+1,0),dp+POS(i,0),100*blen+1);
    int x=a[b[i]];
    for(j=100*blen;j>=x;j--){
      if(dp[POS(i,j-x)]){
	dp[POS(i+1,j)]=1;
      }
    }
  }
  for(i=0;i<(1<<clen);i++){
    int64 sum=0;
    for(j=0;j<clen;j++){
      if((i>>j)&1){
	sum+=a[c[j]];
      }
    }
    if(x-sum>=0 && x-sum<=100*blen && dp[POS(blen,(int)(x-sum))]){
      x-=sum;
      break;
    }
  }
  if(i>=(1<<clen)){
    printf("No\n");
    return;
  }
  char *ans=(char *)calloc(n+1,sizeof(char));
  for(j=0;j<clen;j++){
    ans[c[j]]=((i>>j)&1)?'o':'x';
  }
  int y=(int)x;
  for(i=blen-1;i>=0;i--){
    if(dp[POS(i,y-a[b[i]])]){
      ans[b[i]]='o';
      y-=a[b[i]];
    } else {
      ans[b[i]]='x';
    }
  }
  puts(ans);
}

int main(void){
  run();
  return 0;
}