def get_string(dct):
    if len(dct) == 0:
        return ''

    result = ['^']
    for index, key in enumerate(dct):
        value = dct[key]
        if index == 0:
            result.append(f'@^{key}={value}')
        else:
            result.append(f'@{key}={value}')
    return ','.join(result)

print(get_string({}))