Seoul's government consists of the Seoul Metropolitan Government, which is the executive branch, and the Seoul Metropolitan Council, the legislative body. The administrative structure contains three tiers: si (city), gu (district), and dong (neighborhood; literally, “village”). The mayor of the metropolitan government and the mayors of the gu are elected to four-year terms. Serving under the mayors at both levels are vice mayors and directors of bureaus, offices, and divisions. The Seoul Metropolitan Council is headed by a chairman and two vice chairmen and includes standing committees, special committees, and a secretariat; it has more than 100 members, who serve four-year terms. Most council members are elected to represent their respective districts; ten other members are elected on the basis of proportional representation.