#include<stdio.h>
#include<string.h>
int main()
{
	char a[20];
    gets(a);
    int i;
    int n=0;
    for(i=0;i<strlen(a);i++){
    	if(a[i]>='0'&&a[i]<='9'){
    		n++;
		}
		if((a[i]>='a'&&a[i]<='z')||(a[i]>='A'&&a[i]<='Z')){
			n++;
		}
	}
	printf("%d",n);
	return 0;
 } 

https://www.luogu.com.cn/record/95470849