#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,xt,xl,count; n = xt = xl = 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; }