T151T1

#include<bits/stdc++.h>

using namespace std;

#define gc c=getchar()
#define r(x) read(x)
#define ll long long

template<typename T>
inline void read(T&x){
    x=0;T k=1;char gc;
    while(!isdigit(c)){if(c=='-')k=-1;gc;}
    while(isdigit(c)){x=x*10+c-'0';gc;}x*=k;
}

const int N=150;

struct Int{
    int n;
    int a[N];

    inline int& operator [](const int &x){
        return a[x];
    }

    inline const int & operator [](const int &x)const{
        return a[x];
    }

    inline Int(){
        n=0;
        memset(a,0,sizeof(a));
    }

    inline Int (int x){
        n=0;
        memset(a,0,sizeof(a));
        while(x){
            a[n++]=x%10;
            x/=10;
        }
    }

};

inline Int operator +(const Int &a,const Int &b){
    int n=max(a.n,b.n);
    Int ret;
    for(int i=0;i<n;++i){
        ret[i]=a[i]+b[i];
    }
    for(int i=0;i<n;++i){
        if(ret[i]>9)ret[i]-=10,ret[i+1]+=1;
    }
    while(ret[n]){
        if(ret[n]>9)ret[n]-=10,ret[n+1]+=1;
        n++;
    }
    ret.n=n;
    return ret;
}

inline Int operator -(const Int &a,const Int &b){
    int n=max(a.n,b.n);
    Int ret;
    for(int i=0;i<n;++i){
        ret[i]=a[i]-b[i];
    }
    for(int i=0;i<n;++i){
        if(ret[i]<0)ret[i]+=10,ret[i+1]-=1;
    }
    while(n&&!ret[n])n--;
    ret.n=n+1;
    return ret;
}

inline Int operator *(const Int &a,const Int &b){
    if(!a.n)return a;
    if(!b.n)return b;
    Int ret;
    int n=a.n+b.n-1;
    for(int i=0;i<a.n;++i){
        for(int j=0;j<b.n;++j){
            ret[i+j]+=a[i]*b[j];
        }
    }
    for(int i=0;i<n;++i){
        if(ret[i]>9)ret[i+1]+=ret[i]/10,ret[i]%=10;
    }
    while(ret[n]){
        if(ret[n]>9)ret[n+1]+=ret[n]/10,ret[n]%=10;
        n++;
    }
    ret.n=n;
    return ret;
}

inline Int mul2(const Int &a){
    return a+a;
}

inline Int div2(const Int &a){
    Int ret=a;
    int n=a.n;
    for(int i=n-1;~i;--i){
        if(ret[i]&1)ret[i-1]+=10;
        ret[i]>>=1;
    }
    while(n&&!ret[n-1])--n;
    ret.n=n;
    return ret;
}

inline bool cmp(const Int &a,const Int &b){
    if(a.n!=b.n)return a.n>b.n;
    int n=a.n-1;
    for(int i=n;~i;--i){
        if(a[i]!=b[i])return a[i]>b[i];
    }
    return 0;
}

inline void print(const Int &a){
    for(int i=a.n-1;~i;--i){
        putchar(a[i]+'0');
    }
    puts("");
}

inline Int gcd(const Int &a,const Int &b){
    if(a.n==0)return b;
    if(b.n==0)return a;
    if(!(a[0]&1)&&!(b[0]&1))return mul2(gcd(div2(a),div2(b)));
    if((a[0]&1)&&(b[0]&1))return cmp(a,b)?gcd(a-b,b):gcd(b-a,a);
    if(a[0]&1)return gcd(a,div2(b));
    if(b[0]&1)return gcd(div2(a),b);
//  assert(0);
}

int n,r,tot;
Int ans,R;

int val[N];
int ID[N];
char str[N];


int main(){
    freopen("bijection.in","r",stdin);
    freopen("bijection.out","w",stdout);
    r(n),r(r);R=r;
    scanf("%s",str);
    for(int i=0;i<n;++i){
        if(!ID[str[i]-'a']){
            ID[str[i]-'a']=++tot;
        }
    }
    if(tot<r){
        for(int i=1;i<=tot;++i){
            Int ret;
            for(int j=0;j<n;++j){
                ret=ret*R+(ID[str[j]-'a']==i);
            }
            ans=gcd(ans,ret);
        }
    }
    else {
        for(int i=0;i<n;++i){
            ans=ans*R+ID[str[i]-'a']%r;
        }
        Int mx;
        for(int i=0;i<n;++i){
            mx=mx*R+(ID[str[i]-'a']==1);
        }
        for(int i=2;i<=tot;++i){
            Int ret;
            for(int j=0;j<n;++j){
                ret=ret*R+(ID[str[j]-'a']==i);
            }
            ans=gcd(ans,mx-ret);
        }
    }
    print(ans);
    return 0;
}
/*
100 10
abcdeabcdeabcdeabcdeabcdeabcdeabcdeabcdeabcdeabcdeabcdeabcdeabcdeabcdeabcdeabcdeabcdeabcdeabcdeabcde
*/