Code:
#include<cstdio>
#include<cstdlib>
#include<vector>
#include<string>
#include<iostream>
#include<sstream>
#include<cmath>
using namespace std;
main() {
int a;
int check;
string n, m, s;
vector <string> v;
vector <int> iv;
n.clear();
while(getline(cin,n)){
v.push_back(n);
vector <string> v;
vector <int> iv;
n.clear();
while(getline(cin,n)){
v.push_back(n);
n.clear();
if(v[0]!= "P2"){
return 0;
}
//stringstream ss(n);
//ss >> a;
// v.push_back(n);
a = atoi(n.c_str());
stringstream ss(n);
ss >> a;
if (a <0){
return 0;
}
}
}