#include<stdio.h>
#include<ctype.h>
#include<string.h>
int main(){
    char str[25];
    int len,i,lastLen=0;
    fgets(str,sizeof(str),stdin);
    len=strlen(str);
    if(str[len-1]=='\n'){
        str[len-1]='\0';
        len--;
    }
    for(i=0;i<len;i++){
        if((unsigned char)str[i]<32 || (unsigned char)str[i]>126){
            printf("Invalid input\n");
            return 0;
        }
    }
    int foundLetter=0;
    for(i=len;i>=0;i--){
        if(str[i]!=''){
            lastLen++;
            foundLetter=1;
        }
        else if(foundLetter){
            break;
        }
    }
    printf("%d\n",lastLen);
    return 0;
}