12 lines
199 B
C++
12 lines
199 B
C++
#include<cstdio>
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double a,b,c;
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int main()
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{
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#ifdef local
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freopen("pro.in","r",stdin);
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#endif
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while(scanf("%lf%lf%lf",&a,&b,&c)==3)
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printf("%.5lf\n",(a*b+b*(b-1))/((a+b)*(a+b-c-1)));
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return 0;
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}
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