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#include <iostream>
using namespace std;
int main()
{int res = 0;for(int i = 1; i < 2021; i ++){int b = i;while(b){if (b % 10 == 2) res ++;b /= 10;}}cout << res; return 0;
}
#include <iostream>
using namespace std;
int main()
{int res = 0;for(int i = 1; i < 2021; i ++){int b = i;while(b){if (b % 10 == 2) res ++;b /= 10;}}cout << res; return 0;
}