#include<bits/stdc++.h> #define int long long using namespace std; namespace Fast{ inline int fr(){ register int x = 0,f = 1; static char c = getchar(); while (c < '0' || c > '9'){ if (c == '-'){ f = -1; } c = getchar(); } while (c >= '0' && c <= '9'){ x = (x << 1) + (x << 3) + (c ^ 48); c = getchar(); } return x * f; } inline void fw(int x){ if (x == 0){ putchar('0'); return ; } if (x < 0){ putchar('-'); x = -x; } stack <char> s; while (x){ s.push(x % 10 + 48); x /= 10; } while (!s.empty()){ putchar(s.top()); s.pop(); } } inline void DEBUG(){ puts("awa"); } inline void CCF(){ ios::sync_with_stdio(false); cin.tie(0),cout.tie(0); } } using namespace Fast; signed main(){ int n = fr(); fw(n * 50LL); return 0; }