delete update at signin
delete update at signin

volanja/study-isucon3-yosen,volanja/study-isucon3-yosen,volanja/study-isucon3-yosen,volanja/study-isucon3-yosen,volanja/study-isucon3-yosen,volanja/study-isucon3-yosen,volanja/study-isucon3-yosen,volanja/study-isucon3-yosen,volanja/study-isucon3-yosen