#include<iostream>
#include<cstring>
using namespace std;
int main()
{
string a1;
int a[1001],lena,n;
cin>>n>>a1;
memset(a,0,sizeof(a));
lena=a1.length();
for(int i=1;i<=lena;i++)
a[i]=a1[i-1]-48;
int x=0;
for(int i=1;i<=lena;i++)
x=(x*10+a[i])%n;
if(x==0) x=n;
cout<<x;
}

/*
#include<iostream>
#include<cstring>
using namespace std;
int main()
{
char a1[1001];
int a[1001],lena,n;
cin>>n;
gets(a1);
memset(a,0,sizeof(a));
lena=strlen(a1)-1;
for(int i=1;i<=lena;i++)
a[i]=a1[i]-48;
int x=0;
for(int i=1;i<=lena;i++)
x=(x*10+a[i])%n;
if(x==0) x=n;
cout<<x;
}*/