n,k=map(int,input().split())
s=input()
r=n-k+1

for i in range(r):
    nw=''.join(list(reversed(s[i:i+k])))
    if i<1:
        s=nw+s[i+k:]
    else:    
        s=s[:i]+nw+s[i+k:]

print(s)