#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(){ char a[1000],b[1000]; int n,a1,b1; cin>>a>>b>>n; a1=strlen(a); b1=strlen(b); if(n<=a1) cout<<a[n-1]; else cout<<b[n-1-a1]; return 0; }