# Periodic String

Problem : Periodic String

``````#include<bits/stdc++.h>
#define DEBUG(x) cerr << #x << " = " << x << endl
#define MOD 1000000007LL
#define INF INT_MAX
#define reset(arr,n,i) fill(arr, arr+n, i)
#define iseql(a,b) ((abs(a-b) - 1e-9 < 0) ? 1 : 0)

using namespace std;

int main(){
#ifndef ONLINE_JUDGE
freopen("input.txt","r",stdin);
freopen("output.txt","w",stdout);
#endif
ios::sync_with_stdio(0);
cin.tie(0); cout.tie(0);

long long n,m;
cin >> n >> m;
long long pow2[150001];
pow2[0] = 1;
for(int i=1;i<150001;i++)
pow2[i] = (2LL*pow2[i-1])%m;
vector<long long> fact;
long long ans = 0;
if(n == 1)
ans = 2LL;
for(int i=n-1;i>0;i--)
if(n%i == 0){
bool flag = true;
for(int j=0;j<fact.size();j++){
if(fact[j]%i == 0){
flag = false;
break;
}
}
if(flag){
ans += pow2[i];
ans %= m;
fact.emplace_back(i);
}
}
ans = pow2[n]-ans;
ans %= m;
if(ans < 0) ans += m;
cout << ans << endl;

return 0;
}
``````

I only got 20 points. I am not getting where i am going wrong . Please help.

Thanksâ€¦