#include<stdio.h>
#include<string.h>
struct Data
{
    char str[101];
    char ch;
};
int countChar(struct Data d)
{
    int count =0;
    for(int i=0;d.str[i]!=0;i++)
    {
        if(d.str[i]==d.ch)
        {
            count++;
        }
    }
    return count;
}
int main()
{
    struct Data d;
    scanf("%s",d,str);
    scanf("%c",&d.ch);
    int result =countChar(d);
    if(result ==0)
    printf("-1");
    else
    printf("%d",result);
    return 0;
}