'struct std::pair

I made a pair of vectors and want to initialize values to those pairs using make pair but i get this ERROR:: "'struct std::pair' has no member named 'push_back' "Here is my code.

                       const int maxm=100005;//10^5
                       vector<pair<int,int> > v(maxm);
                       int main(){
                       int n;
                          scanf("%d",&n);
                           for(int i=0;i<n;i++){
                          int x, y;
                         scanf("%d %d",&x,&y);
                        v[i].push_back(make_pair(x,y));
                           }