#include<stdio.h>
#include<string.h>
#include<ctype.h>
int main()
{char s[25];
int i, len, lastlen=0
fgets(s. sizeof(s). stdin);
len=strlen(s);
if(s[len-1]=='\n)
{s[len-1]='\0';
len--;
}
for(i=0:i< len;i++)
{if(!(isalpha(s[i])//isspace(s[I])))
printf("invalid input\n");
return 0;
}
}
i=len-1;
while(i>=0&& isspace(s[i]))0i--;
while(i>=0&& isalpha(s[i]))){lastlen++;
i--;
}
printf("%d\n".lastlen);
return0;
}