=IF(ISERR(FIND("県",LEFT(A2,4),1)),
IF(ISERR(FIND("都",LEFT(A2,3),1)),
IF(ISERR(FIND("道",LEFT(A2,3),1)),
IF(ISERR(FIND("府",LEFT(A2,3),1)),"N/A",
LEFT(A2,FIND("府",A2,1))),
LEFT(A2,FIND("道",A2,1))),
LEFT(A2,FIND("都",A2,1))),
LEFT(A2,FIND("県",A2,1)))