def unwrap(val):
    return chr((val & 0x7f)+32) + chr((val >> 7)+32)

def decrypt(C, tot_sum):
    res = ""
    for i in range(15):
        v = tot_sum - C[i]
        v = v ^ ((i << 5) | i)
        res += unwrap(v)
    return res

if __name__ == "__main__":
    C = [897, 3313, 3231, 3759, 1914, 3119, 9385, 9771, 7570, 1843, 1687, 9972, 2015, 3711, 1953]
    tot_sum = 11938
    
    flag_found = decrypt(C, tot_sum)
    print flag_found