属于这两组的第一个数字：
515,545,818,10101,20202,30303,40404,50505,51515,54545,60606,70707,80808,81818,90909,101010,121212,131313,141414,151515,161616,171717,181818,191919,202020,212121,232323,242424,252525,262626,272727,282828,292929,303030,313131,323232,343434,353535,363636,373737,383838,393939,404040,414141,424242,434343,454545,464646,474747,484848,494949,505050,515151,525252,535353,545454,565656,575757,585858,595959,606060,616161,626262,636363,646464,656565,676767,686868,696969,707070,717171,727272,737373,747474,757575,767676,787878,797979,808080,818181,828282,838383,848484,858585,868686,878787,898989,909090,919191,929292,939393,949494,959595,969696,979797,989898,1010101,2020202,2121212,2727272,3030303,4040404,4242424,5050505,5151515,5252525,5454545,5757575,6060606,6363636,7070707,8080808,8181818,8484848,9090909,10101010,12121212,13131313,14141414,15151515,16161616,17171717,18181818,19191919,20202020,21212121,23232323,24242424,25252525,26262626,27272727,28282828,29292929,30303030,31313131,32323232,34343434,35353535,36363636,37373737,38383838,39393939,40404040,41414141,42424242,43434343,45454545,46464646,47474747,48484848,49494949,50505050,51515151,52525252,53535353,54545454,56565656,57575757,58585858,59595959,60606060,61616161,62626262,63636363,64646464,65656565,67676767,68686868,69696969,70707070,71717171,72727272,73737373,74747474,75757575,76767676,78787878,79797979,80808080,81818181,82828282,83838383,84848484,85858585,86868686,87878787,89898989,90909090,91919191,92929292,93939393,94949494,95959595,96969696,97979797,98989898,101010101,202020202,212121212,272727272,303030303,404040404,424242424,505050505,515151515,525252525,545454545,575757575,606060606,636363636,707070707,808080808,818181818,848484848,909090909,1010101010,1212121212,1313131313,1414141414,1515151515,1616161616,1717171717,1818181818,1919191919.