#include<string.h>#include<cstdio>#define MAXN 10000int lastdigit(char* buf)//f(n) = （f(n/5) * 5^(n/5)）* g(n){ const int mod[20]= {1,1,2,6,4,2,2,4,2,8,4,4,8,4,6,8,8,6,8,2}; int len=strlen(buf),a[MAXN],i,c,ret=1; if (len==1) return mod[buf[0]-'0']; for (i=0; i<len; i++) a[i]=buf[len-1-i]-'0'; for (; len; len-=!a[len-1]) { ret=ret * mod[ a[1]%2*10+a[0] ] % 5; for (c=0,i=len-1; i>=0; i--) c=c*10+a[i],a[i]=c/5,c%=5; } return ret+ret%2*5;}int main(){ char a[10000]; while(scanf("%s",a)!=EOF) { printf("%dn",lastdigit(a)); } return 0;}
