#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);
    
}