#include<iostream> // cin\cout\endl #include<cstdio> //scanf()\printf() #include<cstring> // strcpy()\strcat()\strcmp()\strlen()\memset() #include<cmath> //sqrt()\pow()\abs()\ceil()\floor()\max()\min() using namespace std; int main(){ int n=0,xt=0,xl=0,count=0; while(n<1000){ xt++; if(xt==21) xt=1; xl++; if(xl==31) xl=1; if(xt==xl) count++; n++; } cout<<count<<endl; return 0; }