#pragma GCC optimize ("Ofast") #include using namespace std; template inline S max_L(S a,T b){ return a>=b?a:b; } inline int my_getchar_unlocked(){ static char buf[1048576]; static int s = 1048576; static int e = 1048576; if(s == e && e == 1048576){ e = fread_unlocked(buf, 1, 1048576, stdin); s = 0; } if(s == e){ return EOF; } return buf[s++]; } inline void rd(long long &x){ int k; int m=0; x=0; for(;;){ k = my_getchar_unlocked(); if(k=='-'){ m=1; break; } if('0'<=k&&k<='9'){ x=k-'0'; break; } } for(;;){ k = my_getchar_unlocked(); if(k<'0'||k>'9'){ break; } x=x*10+k-'0'; } if(m){ x=-x; } } struct MY_WRITER{ char buf[1048576]; int s; int e; MY_WRITER(){ s = 0; e = 1048576; } ~MY_WRITER(){ if(s){ fwrite_unlocked(buf, 1, s, stdout); } } } ; MY_WRITER MY_WRITER_VAR; void my_putchar_unlocked(int a){ if(MY_WRITER_VAR.s == MY_WRITER_VAR.e){ fwrite_unlocked(MY_WRITER_VAR.buf, 1, MY_WRITER_VAR.s, stdout); MY_WRITER_VAR.s = 0; } MY_WRITER_VAR.buf[MY_WRITER_VAR.s++] = a; } inline void wt_L(char a){ my_putchar_unlocked(a); } inline void wt_L(const char c[]){ int i=0; for(i=0;c[i]!='\0';i++){ my_putchar_unlocked(c[i]); } } template inline T pow2_L(T a){ return a*a; } template inline T GCD_L(T a, U b){ T r; while(b){ r=a; a=b; b=r%a; } return a; } inline long long Isqrt_s_L(const long long n){ long long r = sqrt(n); r =max_L(r-2, 0); while((pow2_L((r+1)))<= n ){ r++; } if(r*r!=n){ r = -1; } return r; } int main(){ long long A; long long B; long long X; rd(A); rd(B); X =GCD_L(A, B); if(Isqrt_s_L(X)==1){ wt_L("Odd"); wt_L('\n'); } else{ wt_L("Even"); wt_L('\n'); } return 0; } // cLay varsion 20200509-1 // --- original code --- // { // ll A, B, X; // rd(A,B); // X = gcd(A,B); // if(Isqrt_s(X)==1) wt("Odd"); else wt("Even"); // }