parts = input().strip().split()
op = parts[0]

if op == 'D':
    c = parts[1]
    if c in s:
        s = s.replace(c, '', 1)
    else:
        print("指定字符不存在")
elif op == 'I':
    a1, a2 = parts[1], parts[2]
    idx = s.rfind(a1)
    if idx == -1:
        print("指定字符不存在")
    else:
        s = s[:idx] + a2 + s[idx:]
elif op == 'R':
    a1, a2 = parts[1], parts[2]
    if a1 in s:
        s = s.replace(a1, a2)
    else:
        print("指定字符不存在")

print(s)