#include<iostream> // cin\cout\endl #include<cstdio> //scanf()\printf() #include<cstring> // strcpy()\strcat()\strcmp()\strlen()\memset() #include<cmath> //sqrt()\pow()\abs()\ceil()\floor()\max()\min() using namespace std; int main(){ int a,b,c; scanf("%1d%1d%1d",&a,&b,&c); printf("%.3d",(a+b+c)/3); return 0; }l'l'l'l'l'l'l'l'l'l'l'l'l'l'l'l'l'l'llllllllllllllllllll