Re: Can "cout" do evil?

#include<iostream>
#include<vector>
#include<map>
#include<set>
#include<iterator>
#include<string>
#include<algorithm>

using namespace std;

#define M 1000009

vector<int> primes;

//generate C(n, 1), C(n, 2), ...
void dfs(vector<int> &mp, int its, int i, vector<int> &temp){
   if(i==0) {
       int s=1;
       for(vector<int>::iterator it2(temp.begin()); it2!=temp.end();
it2++){ s=s*(*it2); }
       if(s>1) mp.push_back(s); return;
   }
   if(mp[its]==0) return;
   int my_its(its);
   for(vector<int>::iterator it_t(mp.begin() + its); *it_t!=0; it_t+
+, my_its++){
       temp.push_back(*it_t);
       dfs(mp, my_its+1, i-1, temp);
       temp.pop_back();
   }
}

int main(){
   vector<int> numbers; numbers.resize(M, 0);

//generate prime numbers
   primes.push_back(2);
   for(int i=3; i<M; i+=2){
       if(numbers[i]==1) continue;
       primes.push_back(i);
       for(int j=i+i; j<M; j+=i)
           numbers[j] = 1;
   }

   int m, k;
   while(cin>>m>>k){
       vector<int> mprime; int mm=m;
       cout<<1; //<1>

//prime factors of m
       for(vector<int>::iterator it(primes.begin()); it!=primes.end()
&&*it<=mm; it++){
           if(mm%(*it)==0) mprime.push_back(*it);
           while(mm%(*it)==0) mm=mm/(*it);
       }

//generate C(n,i), push the multiplication result of the "i" factors
in mprime, seperated by 0
       int msize = mprime.size();
       mprime.push_back(0);
       for(int i=2; i<=msize; i++){
           vector<int> temp;
           dfs(mprime, 0, i, temp);
           mprime.push_back(0);
       }

//calculate the k-th number x with gcd(x,m)=1
       int result = 0; int total=0; bool change=true;
       while(total<k){
           result += (k-total); total=result;
           for(vector<int>::iterator it(mprime.begin()); it!
=mprime.end()&&*it<=m&&*it<=result; it++){
               if(*it==0){ change=(change?false:true); continue;}
               if(change) total-=(result/(*it));
               else total+=(result/(*it));
           }
       }
       cout<<result<<endl;
   }
}

---------code--------
The above is the code to calculate the k-th number x of m having
gcd(x,m)=1
notice the line marked <1>
If the <1> line exists, everything works fine.
But if I remove line <1>, the guy says error.
what's wrong? Can a simple "cout" do anything evil?