#include<stdio.h>
#include<string.h>
struct dat{
    char w[101],c;
};
int count (sruct data d)
{
    int a=0;
    for (int i=0,i<strlen(d.w);i++){
        if(d.w[i]==d.c){
            a++;
        }
    }
    return(a>0)? a:-1;
    
}
int main()
{
    struct data d;
    scanf("%s",d.w);
    scanf(" %c",&d.c);
    int r=count(d);
    print("%d\n",r);
    return 0;
}