#include <bits/stdc++.h>
using namespace std;
#define int long long
signed main() {
    int a,b,c;
    char s1,s2,s3,s4,s5,s6;
    cin>>a>>s1>>b>>s2>>s3>>s4>>s5>>s6>>c;
    int ans=c-b-1;
    cout<<ans;
    return 0;
}
// 64 位输出请用 printf("%lld")