#include<stdio.h>
#include<string.h>

struct WordData {
    char word[101];
    char letter;
};

int countOccurrence(struct WordData w) {
    int count = 0;
    for(int i=0;i<strlen(w.word);i++)
    {
        if(w.word[i] == w.letter) {
            count++;
        }
    }
return count;    
}
int main()
{
    struct WordData data;
    scanf("%s",data,word);
    scanf(" %c",&data.letter);
    int result = countOccurrence(data);
    if(result == 0)
    {
        printf("-1");
    }
    else
    {
        printf("%d",result);
    }
    return 0;
}